SPI0_C1 field descriptions (continued)Field Description0 Interrupts from SPRF and MODF are inhibited—use polling1 Request a hardware interrupt when SPRF or MODF is 16SPESPI system enableThis bit enables the SPI system and dedicates the SPI port pins to SPI system functions. If SPE iscleared, the SPI is disabled and forced into an idle state, and all status bits in the S register are reset.0 SPI system inactive1 SPI system enabled5SPTIESPI transmit interrupt enableThis is the interrupt enable bit for SPI transmit buffer empty (SPTEF). An interrupt occurs when the SPItransmit buffer is empty (SPTEF is set).0 Interrupts from SPTEF inhibited (use polling)1 When SPTEF is 1, hardware interrupt requested4MSTRMaster/slave mode selectThis bit selects master or slave mode operation.0 SPI module configured as a slave SPI device1 SPI module configured as a master SPI device3CPOLClock polarityThis bit selects an inverted or non-inverted SPI clock. To transmit data between SPI modules, the SPImodules must have identical CPOL values.This bit effectively places an inverter in series with the clock signal either from a master SPI device or to aslave SPI device. Refer to the description of “SPI Clock Formats” for details.0 Active-high SPI clock (idles low)1 Active-low SPI clock (idles high)2CPHAClock phaseThis bit selects one of two clock formats for different kinds of synchronous serial peripheral devices. Referto the description of “SPI Clock Formats” for details.0 First edge on SPSCK occurs at the middle of the first cycle of a data transfer1 First edge on SPSCK occurs at the start of the first cycle of a data transfer1SSOESlave select output enableThis bit is used in combination with the mode fault enable (MODFEN) bit in the C2 register and the master/slave (MSTR) control bit to determine the function of the SS pin.0 When MODFEN is 0: In master mode, SS pin function is general-purpose I/O (not SPI). In slave mode,SS pin function is slave select input.When MODFEN is 1: In master mode, SS pin function is SS input for mode fault. In slave mode, SSpin function is slave select input.1 When MODFEN is 0: In master mode, SS pin function is general-purpose I/O (not SPI). In slave mode,SS pin function is slave select input.When MODFEN is 1: In master mode, SS pin function is automatic SS output. In slave mode: SS pinfunction is slave select input.Table continues on the next page...Memory Map and Register DescriptionsKL25 Sub-Family Reference Manual, Rev. 3, September 2012662 Freescale Semiconductor, Inc.
