− | PXI is the inter-processor communication interface between the ARM7 and ARM9. Most user code runs on the ARM7 and makes requests to the ARM7 to access various hardware (SD, NAND, AES, etc). Each module is identified by a tag. | + | PXI is the inter-processor communication interface between the ARM7 and ARM9. Most user code runs on the ARM9 and makes requests to the ARM7 to access various hardware (SD, NAND, AES, etc). Each module is identified by a tag. |