Serial Interface: Difference between revisions
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m (fix copypasta? SI is at 0480 not 0440) |
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{{#invoke:Register table|head|550px|SI_PIF_AD_RD4B <code>0x0480 0014</code>}}
{{#invoke:Register table|row|31:24}}
| U-0 || U-0 || U-0 || U-0 || U-0 || U-0 || U-0 || U-0
|-
| — || — || — || — || — || — || — || —
{{#invoke:Register table|row|23:16}}
| U-0 || U-0 || U-0 || U-0 || U-0 || U-0 || U-0 || U-0
|-
| — || — || — || — || — || — || — || —
{{#invoke:Register table|row|15:8}}
| RW-0 || RW-0 || RW-0 || RW-0 || RW-0 || RW-0 || RW-0 || RW-0
|-
| - || - || - || - || - || colspan="3" | PIF_ADDR[10:8]
{{#invoke:Register table|row|7:0}}
| RW-0 || RW-0 || RW-0 || RW-0 || RW-0 || RW-0 || U-0 || U-0
|-
| colspan="6" | PIF_ADDR[7:2] || 0 || 0
{{#invoke:Register table|foot}}
{{#invoke:Register table|definitions
| 31-11 | Undefined | Initialized to <code>0</code>
| 10-2 | PIF_ADDR[10:2] | Address in PIF_ROM/PIF_RAM to read data from. Writing to this field should start the DMA transfer, but it actually doesn't work (nothing is transferred).
}}
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.
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.
==== <span style="display:none;">0x0480 0018 - SI_STATUS</code> ====
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