NSPI_CNT
| BIT
|
DESCRIPTION
|
| 0-2
|
Baud Rate
|
| 6-7
|
Unused device select.
|
| 12
|
Bus Mode
|
| 13
|
Transfer Mode (0 = read, 1 = write)
|
| 15
|
Trigger (0 = idle, 1 = busy)
|
This register seems to have a bug where the lower 8 bits are shifted up by 16 when reading this register.
NSPI_DONE
Contains 1 when the SPI slave is selected. A 0 is written here on transfer end to deselect the slave.
NSPI_BLKLEN
| BIT
|
DESCRIPTION
|
| 0-20
|
Transfer size
|
| 21-31
|
Unused
|
NSPI_FIFO
| BIT
|
DESCRIPTION
|
| 0-31
|
Data
|
NSPI_STATUS
| BIT
|
DESCRIPTION
|
| 0
|
FIFO Full (0 = not full, 1 = full)
|
NSPI_AUTOPOLL
| BIT
|
DESCRIPTION
|
| 0-7
|
Command
|
| 16-19
|
Timeout (Tries = 31<<Baudrate (from NSPI_CNT) + Timeout)
|
| 24-26
|
Bit offset (0-7)
|
| 30
|
Poll for a set or unset bit
|
| 31
|
1 = Enable/Busy
|
This automatically sends a command to the device and compares the specified bit in the response with bit 30 until it matches or a timeout occurs. Nintendo uses a timeout of 10 which roughly equals 1 second. This is used in Process9 to poll the gamecard SPI flash status register for write operation finished or write enable.
NSPI_INT_MASK
| BIT
|
DESCRIPTION
|
| 0
|
Transfer finished (1 = disabled)
|
| 1
|
Autopoll success (1 = disabled)
|
| 2
|
Autopoll timeout (1 = disabled)
|
NSPI_INT_STAT
| BIT
|
DESCRIPTION
|
| 0
|
Transfer finished (also fires on each autopoll try?)
|
| 1
|
Autopoll success
|
| 2
|
Autopoll timeout
|
Interrupt ID 23 is fired when any of the bits change to 1 except for interrupts masked in NSPI_INT_MASK. Writing 1 to a bit in this register aknowledges the interrupt.