> 3.10.4 | SPI Interface

> The SPI (Serial Peripheral Interface) is located on the IO interface connector of the TC65 Terminal. The SPI is a synchronous serial interface for controlling and data transfer between the TC65 Terminal and a connected application. Only one application can be connected to the Terminal’s SPI.
> The SPI consists of four lines. These are the two data lines SPIDI/SPIDO, the clock line SPICLK and the chip select line SPICS.
> The TC65 Terminal acts as a single master device, e.g. the clock SPICLK is driven by the TC65 Terminal. Whenever the SPICS pin is in a low state, the SPI bus is activated and data can be transferred from the Terminal and vice versa. The SPI interface uses two independent lines for data input (SPIDI) and data output (SPIDO). The interface supports transmission rates up to 6.5Mbit/s. Transfer rates >1.083Mbps and a length of the cable >150mm are not recommended.
> The SPI is only available if the pins 1 and 2 of the IO interface connector are not used as I 2C interface.

> Table 15: | SPI interface – signal description

> Signal name | Pin | Description
> SPICS | 13 | Chip select – selects and activates the external device via a low signal.
> SPIDI | 14 | Data in – serial data input line (from external device to TC65 Terminal)
> I2CDAT_SPIDO | 1 | Data out – serial data output line (from TC65 Terminal to external device)
> I2CCLK_SPICLK | 2 | Serial clock line

> The SPI Interface can be used in 4 different modes. Figure 14 shows the characteristics of these modes.
> Figure 14: Characteristics of SPI modes