Texas Instruments MSC1210 manual Functional Description, 1. SPI block diagram

Models: MSC1210

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Description

13.1 Description

The MSC1210 includes a serial peripheral interface (SPI) module that allows simple and efficient access to SPI-compatible devices via a number of SFRs provided for that purpose. The SPI is an independent serial communications subsystem that allows the MSC1210 to communicate synchronously with SPI peripheral devices and other microprocessors. The SPI is also capable of interprocessor communication in a multiple master system. The SPI system can be configured as either a master or a slave device.

The maximum data transfer rates can be as high as 1/2 the fOSC clock rate (12Mbits per second for a 24MHz fOSC frequency).

13.2 Functional Description

The central element in the SPI system is the block containing the shift register and the read data buffer. SPI data is transmitted and received simultaneously. For every byte that is sent, a byte is also received. The system is double-buffered in the transmit direction and double-buffered in the receive direction. This means that new data for transmission can be written to the SPIDATA register before the previous transfer is complete. Additionally, received data is transferred into a parallel read data buffer, so the shifter is free to accept a second serial character. As long as the first character is read out of the SPIDATA register before the next serial character is ready to be transferred, no overrun condition occurs.

For FIFO operation, the reading of the received data can be delayed up to the length of time it takes to fill the FIFO. The SPIDATA register is used for reading data received, and for writing data to be sent, as shown in Figure 13−1.

Figure 13−1. SPI block diagram

13-2

Page 164
Image 164
Texas Instruments MSC1210 manual Functional Description, 1. SPI block diagram