Abstract
Information communication circuitry, including a first integrated circuit for coupling to a second integrated circuit in a package on package configuration. The first integrated circuit comprises processing circuitry for communicating information bits, and the information bits comprise data bits and error correction bits, where the error correction bits are for indicating whether data bits are received correctly. The second integrated circuit comprises a memory for receiving and storing at least some of the information bits. The information communication circuitry also includes interfacing circuitry for selectively communicating, along a number of conductors, between the package on package configuration. In a first instance, the interfacing circuitry selectively communicates only data bits along the number of conductors. In a second instance, the interfacing circuitry selectively communicates data bits along a first set of the number of conductors and error correction bits along a second set of the number of conductors.
Claims
1. A circuit comprising: first and second data ports; a data bus configured to carry data, the data bus coupled to the first data port; an error code correction (ECC) bus configured to carry ECC bits associated with the data carried in the data bus; and a multiplexer having a first input coupled to the data bus, a second input coupled to the ECC bus, and an output coupled to the second data port.
2. The circuit of claim 1, further comprising an AND gate having an output coupled to a selection input of the multiplexer.
3. The circuit of claim 2, wherein the multiplexer is configured to select the first input when the selection input is high, and the second input when the selection input is low.
4. The circuit of claim 1, further comprising: a first memory having a third data port coupled to the first data port; and a second memory having a fourth data port coupled to the second data port.
5. The circuit of claim 4, further comprising: an ECC data port coupled to the ECC bus; and a fourth memory having a fifth data port coupled to the ECC data port.
6. The circuit of claim 1, further comprising a first memory having a third data port coupled to the first data port, and a fourth data port coupled to the second data port.
7. The circuit of claim 6, further comprising: an ECC data port coupled to the ECC bus; and a second memory having a fifth data port coupled to the ECC data port.
8. The circuit of claim 7, further comprising sixth and seventh data ports coupled to the data bus, wherein the first memory comprises eighth and ninth data ports respectively coupled to the sixth and seventh data ports.
9. The circuit of claim 1, wherein the data bus is a 32-bit bus, and wherein the ECC bus is an 8-bit bus.
10. A device comprising a package comprising: a first die comprising: first and second data ports, a data bus configured to carry data, the data bus coupled to the first data port, an error code correction (ECC) bus configured to carry ECC bits associated with the data carried in the data bus, and a multiplexer having a first input coupled to the data bus, a second input coupled to the ECC bus, and an output coupled to the second data port; and a second die comprising: first and second data ports respectively coupled to the first and second data ports of the first die, and a memory coupled to the first and second data ports.
11. The device of claim 10, wherein the package comprises a ball grid array (BGA), wherein the first die is disposed between the BGA and the second die.
12. The device of claim 10, wherein the first die comprises a processor, and wherein the memory is configured to provide electronic storage to the processor.
13. The device of claim 10, wherein the first die comprises a third data port coupled to the data bus, wherein the third data port is unconnected to the second die.
14. The device of claim 10, wherein the first die comprises a third data port coupled to the ECC bus, wherein the third data port is unconnected to the second die.
15. The device of claim 10, wherein the memory is a double data rate memory.
16. The device of claim 15, wherein the memory is a low power double data rate 2 (LPDDR2) or low power double data rate 3 (LPDDR3) memory.
17. The device of claim 10, wherein the first and second data ports are 8-bit data ports.
18. The device of claim 10, wherein the multiplexer is dynamically selectable based on a address of the memory.
19. The device of claim 18, wherein the multiplexer is configured to provide data at the output of the multiplexer from the ECC bus for a first region of the memory, and provide data from the data bus at the output of the multiplexer for a second region of the memory, wherein, the first region is configured to store 16-bit data and the second region is configured to store 32-bit data.
20. The device of claim 10, wherein the memory does not include dedicated ECC pins.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0011] FIG. 1 illustrates a cross-sectional side view of a prior art integrated circuit package on package (PoP) configuration.
[0012] FIG. 2a illustrates a prior art 32-bit PoP external memory interface
[0013] FIG. 2b illustrates a prior art 16-bit PoP external memory interface.
[0014] FIG. 3 illustrates a combined block and schematic view of an external memory interface in accordance with a preferred embodiment.
[0015] FIG. 4 illustrates a combined block and schematic view of a configuration including interface EMIF.sub.2 of FIG. 3, when connected to a memory MEM for supporting 16-bit critical DATA in a PoP configuration.
[0016] FIG. 5 illustrates a combined block and schematic view of a configuration including interface EMIF.sub.2 of FIG. 3 when connected to a memory MEM for supporting 32-bit non-critical DATA in a PoP configuration.
[0017] FIG. 6 illustrates a memory address space for demonstrating an additional preferred embodiment aspect in connection with dynamic switching to accommodate both critical and non-critical DATA.
[0018] FIG. 7 illustrates an electrical block diagram of interface EMIF.sub.2 in a non-PoP configuration supporting 32-bit DATA with ECC, and using two 16-bit memories MEM.sub.16.1 and MEM.sub.16.2, and a third 16-bit (or 8-bit) memory MEM.sub.16.3 for ECC.
[0019] FIG. 8 illustrates an electrical block diagram of interface EMIF.sub.2 in another non-PoP (e.g., PCB) configuration, which in FIG. 8 again supports 32-bit DATA with ECC, but here using a single 32-bit memory MEM.sub.32 for DATA, along with again a 16-bit (or 8-bit) memory MEM.sub.16.3 for ECC.
[0020] FIG. 9 illustrates an electrical block diagram of interface EMIF.sub.2 in a non-PoP (e.g., PCB) configuration that supports 16-bit DATA with ECC, and using a single 16-bit memory MEM.sub.16.1 for DATA and a single 16-bit (or 8-bit) memory MEM.sub.16.3 for ECC.
DETAILED DESCRIPTION OF EMBODIMENTS
[0021] FIGS. 1, 2a, and 2b were discussed above in the Background Of The Invention section of this document, and the reader is assumed to be familiar with that discussion.
[0022] FIG. 3 illustrates a combined block and schematic view of an external memory interface EMIF.sub.2 in accordance with a preferred embodiment. Interface EMIF.sub.2 communicates information, including DATA and ECC for that DATA, to a memory, the latter of which is shown in later Figures. Interface EMIF.sub.2 may be part of a larger memory interface with physical connectors (e.g., having one or more pins) beyond those shown and discussed below. For example, interface EMIF.sub.2 may be part of a circuit, such as a processor, including a microprocessor or digital signal processor, that includes other connectors as understood by one skilled in the art. Such other connectors, however, are neither shown nor discussed so as to simplify the document. In any event and as detailed in this document, interface EMIF.sub.2 overcomes limitations of the prior art in that it facilitates a combined PoP structure, as between interface EMIF.sub.2 and standard prior art memories, that supports error checking such as ECC. In addition, interface EMIF.sub.2 also may be used in non-PoP configurations, for example with one or more memories located on a PCB.
[0023] In a preferred embodiment, interface EMIF.sub.2 includes a number of physical connectors PHYx, where each such connector PHYx represents a number of bits/pins/conductors for interfacing with an external memory circuit or chip, such as various types of SDRAM including LPDDR2/3 memory chips. For sake of example, each physical connector PHYx provides 8 bits (i.e., a byte) of information, although other sized data quantities could be represented, including a single connector/pin per bit. Nominally, interface EMIF.sub.2 includes four such connectors for DATA, namely, DATA PHY0, DATA PHY1, DATA PHY2, and DATA PHY3, and one such connector for ECC, namely, ECC PHY.sub.ECC. In this sense, therefore, the external connectors of interface EMIF.sub.2 appear the same as a prior art non-PoP (e.g., PCB) interface, operable to connect to a memory that supports four bytes of DATA and one byte of ECC, and indeed interface EMIF.sub.2 also may serve such a role. As detailed below, however, interface EMIF.sub.2 also may serve PoP configurations, preferably including a 16-bit PoP with ECC arrangement, or a 32-bit PoP without ECC arrangement.
[0024] Within interface EMIF.sub.2 are shown an ECC bus and a DATA bus, and interface EMIF.sub.2 further includes Processing Circuitry 40 coupled to each such bus, to illustrate that the device (e.g., processor), including or communicating via EMIF.sub.2, permits Processing Circuitry 40 to process up to X bits of DATA (e.g., X=32) and Y bits of ECC (e.g., Y=8 or less). The lowest first and second DATA bytes B0 (i.e., D[7:0]) and B1 (i.e., D[15:8]) of the DATA bus are connected to respective physical connectors DATA PHY0 and DATA PHY1, and the fourth DATA byte B3 (i.e., D[31:24]) is connected to physical connector DATA PHY3. The third DATA byte B2 (i.e., D23:16), however, is connected as a first input to a multiplexer 42. The sole ECC byte ECC[7:0] (or other number of bits in a different preferred embodiment) is connected to both physical connector ECC PHY.sub.ECC and the second input of multiplexer 42. The output of multiplexer 42 is connected to the physical connector DATA PHY2. The control input of multiplexer 42 is connected to the output of an AND gate 44, which for reasons detailed below has two input signals: (1) PoP_Narrow; and (2) ECC_en. In a preferred embodiment, these two input signals are internally generated (i.e., asserted or de-asserted), such as from register outputs, in response to software as may be run by Processing Circuitry 40 or the like, and consistent with the desired functionality described below.
[0025] FIG. 4 illustrates a combined block and schematic view of a configuration including interface EMIF.sub.2 of FIG. 3, in a first instance, wherein interface EMIF.sub.2 is connected to a memory MEM (e.g., 32-bit SDRAM) for supporting 16-bit critical data in a PoP configuration. By way of illustration, the PoP connectivity in general is shown by a dashed rectangle that includes interface EMIF.sub.2 and memory MEM, as may be generally oriented physically in the manner shown and discussed above in FIG. 1. In FIG. 4, however, the preferred embodiment PoP configuration permits interface EMIF.sub.2 to write, preferably at the same time, 16 DATA bits along with 8 bits of ECC, to memory MEM. At the outset, therefore, note that memory MEM is commercially available for PoP configurations, but such memory does not include dedicated ECC pins, presumably due to the space constraints of PoP considerations. In combination with the preferred embodiment interface EMIF.sub.2, however, additional ECC protection is provided, as explored below.
[0026] In FIG. 4, the physical connectors from interface EMIF.sub.2 of DATA PHY0 and DATA PHY1 of the first and second two DATA bytes B0 and B1, respectively, are connected to respective physical connectors on memory MEM. In addition, the physical connector from interface EMIF.sub.2 of DATA PHY2, which recall is from the output of multiplexer 42, is connected to respective physical connector DATA PHY2 on memory MEM. Lastly, note that physical connector DATA PHY3 for the third byte on memory MEM is left open (i.e., disconnected from interface EMIF.sub.2) so that, in the present configuration, any information at that interface constitutes “don't care” information.
[0027] The operation of the FIG. 4 configuration is now described. Because the configuration is intended to support PoP 16-bit with ECC, then the PoP_Narrow signal is asserted for the narrower option of 16 bits rather than 32 bits, and the ECC_en signal is asserted for including ECC information. In response, the output of AND gate 44 is asserted to that multiplexer 42 selects the ECC[7:0] information and outputs it to the physical connectors DATA PHY2 of both interface EMIF.sub.2 and memory MEM. As a result, during a write of DATA from interface EMIF.sub.2 to memory MEM, memory MEM receives, as its D[15:0], 16 bits of DATA from the interface EMIF.sub.2 DATA bus; at the same time, memory MEM receives, as its D[23:16], 8 bits of ECC from the interface EMIF.sub.2 ECC bus. Note further that while the various Figures and descriptions herein address the writing from interface EMIF.sub.2 to memory MEM, the same preferred embodiment contemplates the reading of memory MEM by interface EMIF.sub.2, in which case multiplexer 42 would serve as a demultiplexer, and the arrow directions depicting information flow in the various Figures would be reversed. In either event, therefore, the FIG. 4 configuration supports ECC communication, even in the PoP environment.
[0028] FIG. 5 illustrates a combined block and schematic view of a configuration including interface EMIF.sub.2 of FIG. 3 in a second instance, wherein interface EMIF.sub.2 is connected to a memory MEM (e.g., 32-bit SDRAM) for supporting 32-bit non-critical data in a PoP configuration. Thus, the FIG. 5 PoP configuration permits interface EMIF.sub.2 to simultaneously write (or read) 32 DATA bits, without ECC. Again, memory MEM is commercially available for PoP configurations. Also in FIG. 5, the physical connectors from interface EMIF.sub.2 of all four data bytes, DATA PHY0, DATA PHY1, DATA PHY2, and DATA PHY3 are connected to respective physical connectors on memory MEM.
[0029] The operation of the FIG. 5 configuration is now described. Because the configuration is intended to support PoP 32-bit without ECC, then neither the PoP_Narrow signal nor the ECC_en signal is asserted. In response, the output of AND gate 44 is de-asserted, so that multiplexer 42 selects the D[23:16] of DATA and outputs it to the physical connectors DATA PHY2 of both interface EMIF.sub.2 and memory MEM. As a result, during a write of DATA from interface EMIF.sub.2 to memory MEM, memory MEM receives DATA from the EMIF.sub.2 DATA bus at each of data inputs D[31:0]. In other words, fully 32 bits of DATA pass between interface EMIF.sub.2 and memory MEM, without any ECC information. Thus, the same preferred embodiment interface EMIF.sub.2 has been shown in FIGS. 4 and 5 to support PoP configurations, wherein one configuration (FIG. 4) supports ECC while another supports higher bandwidth (e.g., 32 bits versus 16 bits) without ECC.
[0030] FIG. 6 illustrates a memory address space 50 for demonstrating an additional preferred embodiment aspect in connection with dynamic switching of multiplexer 42 of FIG. 5, so as to accommodate both critical and non-critical DATA. Specifically, memory address space 50 is intended to illustrate a preferred mapping or storing of DATA within the address space addressable by interface EMIF.sub.2, where as shown each region Rx of the space stores only critical or non-critical DATA but not a combination of the two. With this preferred embodiment partitioning of data storage, further in the preferred embodiment the FIG. 5 PoP configuration may achieve ECC protection in one instance for either the critical DATA regions R1 and R3, 16 bits at a time, or non-ECC protection in a different instance for any of the non-critical DATA regions R0, R2, and R4, 32 bits at a time. For example looking to region R0 which stores non-critical DATA, in the instance when interface EMIF.sub.2 is communicating (e.g., writing) this non-critical DATA to memory MEM, then as indicated graphically in FIG. 6 to the right of that region, AND gate 44 is de-asserted, so that multiplexer 42 selects D[23:16] and outputs that byte B2 of DATA to the DATA PHY2 physical connectors of interface EMIF.sub.2 and memory MEM; at the same time, interface EMIF.sub.2 communicates the other three DATA bytes B0, B1, and B3 on respective connectors PHY0, PHY1, and PHY3. In this instance, therefore, 32 bits of non-critical DATA are communicated without ECC, but in a PoP configuration. To the contrary, however, and for example looking to region R1 which stores critical DATA, when interface EMIF.sub.2 is communicating (e.g., writing) this critical DATA to memory MEM, then as indicated graphically in FIG. 6 to the right of that region, AND gate 44 is asserted, so that multiplexer 42 selects ECC[7:0] and outputs that information to the DATA PHY2 physical connectors of interface EMIF.sub.2 and memory MEM; at the same time, interface EMIF.sub.2 writes the lower two DATA bytes B0 and B1 (and B3 is a don't care). In this instance, therefore, 16 bits of critical DATA are communicated, along with ECC, in a PoP configuration. Thus, FIG. 6 further demonstrates that the FIG. 5 configuration supports dynamic switching so as to communicate either ECC or non-ECC protected DATA, in a PoP configuration.
[0031] FIG. 7 illustrates an electrical block diagram of interface EMIF.sub.2 in a non-PoP (e.g., PCB) configuration that supports 32-bit DATA with ECC, using two 16-bit memories MEM.sub.16.1 and MEM.sub.16.2 for DATA, and a third 16-bit (or 8-bit) memory MEM.sub.16.3 for ECC. First, note that for sake of simplification, the internal schematic items of interface EMIF.sub.2 shown and discussed above are eliminated from the Figure. Further in FIG. 7, the lower two DATA bytes from interface EMIF.sub.2 are connected to communicate two bytes to 16-bit memory MEM.sub.16.1, and the upper two DATA bytes from interface EMIF.sub.2 are connected to communicate two bytes to 16-bit memory MEM.sub.16.2. Further, the 8 bits from the physical connector ECC PHY.sub.ECC of interface EMIF.sub.2 are connected to 8 bits in third memory MEM.sub.16.3. Thus, in the earlier PoP configuration preferred embodiments wherein the physical connector ECC PHY.sub.ECC of interface EMIF.sub.2 is unused, in the FIG. 7 preferred embodiment that additional connector provides support for non-PoP configurations. The FIG. 7 preferred embodiment configuration, therefore, demonstrates that interface EMIF.sub.2 also may be used to support 32 DATA bits plus ECC, preferably in a non-PoP configuration, because the number of memory chips involved is likely to exceed the constrains of PoP configurations.
[0032] FIG. 8 illustrates an electrical block diagram of interface EMIF.sub.2 in another non-PoP (e.g., PCB) configuration, which in FIG. 8 again supports 32-bit DATA with ECC, but here using a single 32-bit memory MEM.sub.32 for DATA, along with again a 16-bit (or 8-bit) memory MEM.sub.16.3 for ECC. In FIG. 8, therefore, each DATA byte from interface EMIF.sub.2 is connected to a respective DATA byte position in memory MEM.sub.32, that is, the first DATA byte from interface EMIF.sub.2 connects to the first DATA byte in 32-bit memory MEM.sub.32, the second DATA byte from interface EMIF.sub.2 connects to the second DATA byte in 32-bit memory MEM.sub.32, and so forth. Further, the 8 bits from the physical connector ECC PHY.sub.ECC of interface EMIF.sub.2 are connected to 8 bits in memory MEM.sub.16.3. The FIG. 8 preferred embodiment configuration, therefore, demonstrates that interface EMIF.sub.2 also may be used to support 32 DATA bits plus ECC using, for the DATA, a single DATA memory chip, as opposed to the two DATA memory chips in FIG. 7. Further, again the physical connector ECC PHY.sub.ECC of interface EMIF.sub.2, unused for PoP configurations, in FIG. 8 provides support for non-PoP configurations.
[0033] FIG. 9 illustrates an electrical block diagram of interface EMIF.sub.2 in a non-PoP (e.g., PCB) configuration that supports 16-bit DATA with ECC, and using a single 16-bit memory MEM.sub.16.1 for DATA and a single 16-bit (or 8-bit) memory MEM.sub.16.3 for ECC. The FIG. 9 preferred embodiment configuration demonstrates that interface EMIF.sub.2 also may be used to support 16 DATA bits plus ECC, preferably in a non-PoP configuration. Additionally, once more, FIG. 9 demonstrates that the physical connector ECC PHY.sub.ECC of interface EMIF.sub.2, unused for PoP configurations, provides support for non-PoP configurations.
[0034] From the above, various embodiments provide numerous improvements to the prior art. Such improvements include circuitry with an external memory interface that provides PoP memory configurations with available ECC support. Moreover, the preferred embodiments contemplate that a same interface can further support alternative functionality within a PoP configuration so that critical data has ECC support, while non-critical data does not, but the latter is afforded greater bandwidth (e.g., 32 bits) than the ECC supported data (e.g., 16 bits). Still further, the same preferred embodiment interface may support one or more non-PoP configurations. Moreover, various aspects have been described, and still others will be ascertainable by one skilled in the art from the present teachings. For example, while multiplexer 42 has been shown as included within the same integrated circuit that comprises Processing Circuitry 40, external glue logic may be used in an alternative embodiment. Thus, while various alternatives have been provided according to the disclosed embodiments, still others are contemplated. Given the preceding, therefore, one skilled in the art should further appreciate that while some embodiments have been described in detail, various substitutions, modifications or alterations can be made to the descriptions set forth above without departing from the inventive scope, as is defined by the following claims.
