Protocol
The communication protocol for normal PXI commands is documented below. The size of cmd_buf is calculated from the cmd_hdr. With newer FIRM the total size for command header + buffer must be at most 0x40 words, otherwise Process9 will panic.
Each pxi_id corresponds to a Process9 PXI command-handler thread which handles the actual command processing. With newer FIRM the pxi_id must be in a certain range.
Request
A11->A9 (u32) pxi_id
A11->A9 (u32) cmd_hdr
A11->A9 (u32[]) cmd_buf
Response
A9->A11 (u32) pxi_id
A9->A11 (u32) cmd_hdr
A9->A11 (u32[]) cmd_buf
Registers
| Old3DS
|
Name
|
Address
|
Width
|
Used by
|
| Yes
|
PXI_SYNC9
|
0x10008000
|
4
|
|
| Yes
|
PXI_????9
|
0x10008003
|
1
|
|
| Yes
|
PXI_CNT9
|
0x10008004
|
4
|
|
| Yes
|
PXI_RECV_FIFO9
|
0x10008008
|
4
|
|
| Yes
|
PXI_SYNC11
|
0x10163000
|
4
|
|
| Yes
|
PXI_CNT11
|
0x10163004
|
4
|
|
| Yes
|
PXI_SEND11
|
0x10163008
|
4
|
|
| Yes
|
PXI_RECV_11
|
0x1016300C
|
4
|
|
The PXI registers are similar to those on DS.
PXI_SYNC
| Bit
|
RW
|
Description
|
| 0-3
|
R
|
Data input from PXI_SYNC Bit8-11 of remote CPU (00h..0Fh)
|
| 8-11
|
R/W
|
Data output to PXI_SYNC Bit0-3 of remote CPU (00h..0Fh)
|
| 13
|
W
|
Send IRQ to remote CPU (0=None, 1=Send IRQ)
|
| 14
|
R/W
|
Enable IRQ from remote CPU (0=Disable, 1=Enable)
|
| 23
|
?
|
?
|
PXI_CNT
| Bit
|
RW
|
Description
|
| 0
|
R
|
Send Fifo Empty Status (0=Not Empty, 1=Empty)
|
| 1
|
R
|
Send Fifo Full Status (0=Not Full, 1=Full)
|
| 2
|
R/W
|
Send Fifo Empty IRQ (0=Disable, 1=Enable)
|
| 3
|
W
|
Send Fifo Clear (0=Nothing, 1=Flush Send Fifo)
|
| 8
|
R
|
Receive Fifo Empty (0=Not Empty, 1=Empty)
|
| 9
|
R
|
Receive Fifo Full (0=Not Full, 1=Full)
|
| 10
|
R/W
|
Receive Fifo Not Empty IRQ (0=Disable, 1=Enable)
|
| 14
|
R/W
|
Error, Read Empty/Send Full (0=No Error, 1=Error/Acknowledge)
|
| 15
|
R/W
|
Enable Send/Receive Fifo (0=Disable, 1=Enable)
|