BECKHOFF EtherCAT IP Core for Altera FPGAs v3.0.10 - Manual (Page 106)

PDI Description
III-94 Slave Controller – IP Core for Altera FPGAs
10.2 SPI Slave Interface
10.2.1 Interface
An EtherCAT device with PDI type 0x05 is an SPI slave. The SPI has 5 signals: SPI_CLK, SPI_DI
(MOSI), SPI_DO (MISO), SPI_SEL and SPI_IRQ
4 :
SPI master
(µController)
SPI_SEL
SPI_CLK
SPI_DI
SPI_DO
SPI_IRQ
SPI slave
(EtherCAT
device)
Figure 40: SPI master and slave interconnection
Table 46: SPI signals
Signal Direction Description Signal polarity
SPI_SEL IN (master → slave) SPI chip select Typical: act. low
SPI_CLK IN (master → slave) SPI clock
SPI_DI IN (master → slave) SPI data MOSI act. high
SPI_DO OUT (slave → master) SPI data MISO act. high
SPI_IRQ OUT (slave → master) SPI interrupt Typical: act. low
10.2.2 Configuration
The SPI slave interface is selected with PDI type 0x05 in the PDI control register 0x0140. It supports
different timing modes and configurable signal polarity for SPI_SEL and SPI_IRQ. The SPI
configuration is located in register 0x0150.
4 The prefix `PDI_` is added to the SPI signals if the EtherCAT IP Core is used.