Deserial Serial Peripheral Interface (DSPI)MPC5566 Microcontroller Reference Manual, Rev. 220-12 Freescale SemiconductorThe following table describes the field in the DSPI transfer count register:20.3.2.3 DSPI Clock and Transfer Attributes Registers 0–7 (DSPIx_CTARn)The DSPI modules each contain eight clock and transfer attribute registers (DSPIx_CTARn) which areused to define different transfer attribute configurations. Each DSPIx_CTAR controls:• Frame size• Baud rate and transfer delay values• Clock phase• Clock polarity• MSB or LSB firstDSPIx_CTARs support compatibility with the QSPI module in the MPC5xx family of MCUs. SeeSection 20.5.4, “MPC5xx QSPI Compatibility with the DSPI,” for a discussion on DSPI and QSPIcompatibility. At the initiation of an SPI or DSI transfer, control logic selects the DSPIx_CTAR thatcontains the transfer attributes. Do not write to the DSPIx_CTARs while the DSPI is running.In master mode, the DSPIx_CTARn registers define combinations of transfer attributes such as frame size,clock phase and polarity, data bit ordering, baud rate, and various delays. In slave mode, a subset of the bitfields in the DSPIx_CTAR0 and DSPIx_CTAR1 registers are used to set the slave transfer attributes. Seethe individual bit descriptions for details on which bits are used in slave modes.Address: Base + 0x0008 Access: R/W0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15R SPI_TCNTWReset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 016 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31R 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0WReset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0Figure 20-4. DSPI Transfer Count Register (DSPIx_TCR)Table 20-4. DSPIx_TCR Field DescriptionsField Description0–15SPI_TCNT[0:15]SPI transfer counter. Counts the number of SPI transfers the DSPI makes. The SPI_TCNT field is incrementedevery time the last bit of an SPI frame is transmitted. A value written to SPI_TCNT presets the counter to that value.SPI_TCNT is reset to zero at the beginning of the frame when the CTCNT field is set in the executing SPIcommand. The transfer counter ‘wraps around,’ incrementing the counter past 65535 resets the counter to zero.16–31 Reserved
