Serial Interface: Difference between revisions
→0x0480 0014 - SI_PIF_AD_RD4B
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This register is broken and doesn't work. It was meant to execute a DMA transfer with a <code>RD4B</code> serial frame with PIF (to read 4 bytes from either PIF-ROM or PIF-RAM), but for some reason it does not work, and nothing is transferred. It is still documented here from completeness.
Any read from this register always returns 0. Also, the SI_DRAM_ADDR register is not modified after a write to SI_PIF_AD_RD4B, as the DMA is not performed.
Notice that VR4300 can still do a 32-bit read from PIF-ROM/PIF-RAM using a direct memory read in the memory mapped space (physical address <code>0x1FC0 0000</code> - <code>0x1FC0 07FF</code> and it will work correctly, though it will be a blocking read that will keep the VR4300 blocked as the serial transfer happens.
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