NSPI_CNT
BIT
|
DESCRIPTION
|
2-0
|
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
|
31-0
|
Transfer size
|
NSPI_FIFO
BIT
|
DESCRIPTION
|
31-0
|
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?
|
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.