BECKHOFF EtherCAT IP Core for Xilinx FPGAs v3.00k - Manual (Page 112)

PDI Description
III-100 Slave Controller – IP Core for Xilinx FPGAs
10.2.5 Commands
The command CMD0 in the second address/command byte may be READ, READ with following Wait
State bytes, WRITE, NOP, or Address Extension. The command CMD1 in the third address/command
byte may have the same values:
Table 49: SPI commands CMD0 and CMD1
CMD[2] CMD[1] CMD[0] Command
0 0 0 NOP (no operation)
0 0 1 reserved
0 1 0 Read
0 1 1 Read with following Wait State bytes
1 0 0 Write
1 0 1 reserved
1 1 0 Address Extension (3 address/command bytes)
1 1 1 reserved
10.2.6 Interrupt request register (AL Event register)
During the address phase, the SPI slave transmits the PDI interrupt request registers 0x0220-0x0221
(2 byte address mode), and additionally register 0x0222 for 3 byte addressing on SPI_DO (MISO):
Table 50: Interrupt request register transmission
Byte
2 Byte address mode 3 Byte address mode
SPI_DI
(MOSI) SPI_DO
(MISO) SPI_DI
(MOSI) SPI_DO
(MISO)
0 A[12:5] I0[7:0] interrupt request
register 0x0220 A[12:5] I0[7:0] interrupt request register
0x0220
1 A[4:0]
CMD0[2:0] I1[7:0] interrupt request
register 0x0221 A[4:0]
CMD0[2:0] I1[7:0] interrupt request register
0x0221
2 (Data phase) A[15:13]
CMD1[2:0] I2[7:0] interrupt request register
0x0222
10.2.7 Write access
In the data phase of a write access, the SPI master sends the write data bytes to the SPI slave
(SPI_DI/MOSI). The write access is terminated by taking back SPI_SEL after the last byte. The
SPI_DO signal (MISO) is undetermined during the data phase of write accesses.
10.2.8 Read access
In the data phase of a read access, the SPI slave sends the read data bytes to the SPI master
(SPI_DO/MISO).