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Modules | |
| SPI config parameters | |
| SPI structures and constants | |
| SPI functions | |
Detailed Description
The SPI module is used for communication between the DOLPHIN IC and a HOST using the SPI protocol. The SPI module supports communication where the DOLPHIN acts as SPI-Master and the HOST acts SPI-Slave.
The SPI module supports packet transmission. The size of one packet can be 1,2,3 or 4 bytes. The CS can't be modified during packet transmission. The maximum speed of one packet transmission is 2Mbit. Between two packets a certain processing delay is needed called interpacket delay. size of the interpacket delay depends on the following factors:
- duplex mode (half duplex smaller delay)
- packet size (the bigger packet, the more delay between packets)
- other active interrupts
The interpacket delay + the packet transmission speed gives the real SPI communication speed. The following table shows the real SPI speed for different packet size @ 2MHz packet clock speed.
The initialization of the SPI module is done through Dolphin APIConfigurator. The generated settings are saved to the file EO3100I_CFG.h.
The SPI interfaces uses the following pins:
- SCSEDIO0 - Chip select (CS)
- SCLKDIO1 - SPI clock (CLK)
- WSDADIO2 - Master In Slave Out (MISO)
- RSDADIO3 - Master Out Slave In (MOSI)
There are two possibilities how control CS (configured with spi_init with the parameters).
- manual CS mode
- automatic CS mode
To manualy controll the CS the function spi_setCS is used. In automatic CS the CS raised and lowered between each packet automaticly.
- Note:
- In order to determine the real SPI communication speed, be sure to measure the interpacket delay for data that is larger than 4 byte and also calculate with the duration of interrupts that can make the interpacket delay larger.
- Be sure when using both SPI and UART module that the UART module is not configured for pins WSDADIO2, RSDADIO3.