MCF51QE128 MCU Series Reference Manual, Rev. 3
324 Freescale Semiconductor
Get the latest version from freescale.com
16.4.4 SPI Status Register (SPIxS)

This register has three read-only status bits. Bits 6, 3, 2, 1, and 0 are not reserved and always read 0. Writes

have no meaning or effect.

Table 16-4. SPIxBR Register Field Descriptions

Field Description
7 Reserved, should be cleared.
6–4
SPPR
SPI Baud Rate Prescale Divisor. This 3-bit field selects one of eight divisors for the SPI baud rate prescaler as
shown below. The input to this prescaler is the bus rate clock (BUSCLK). The output of this prescaler drives the
input of the SPI baud rate divider (see Figure 16-4).
3 Reserved, should be cleared.
2–0
SPR
SPI Baud Rate Divisor. This 3-bit field selects one of eight divisors for the SPI baud rate divider as shown below.
The SPI baud rate prescaler supplies the input to this divider (see Figure 16-4). The output of this divider is the
SPI bit rate clock for master mode.
76543210
R SPRF 0 SPTEF MODF 0 0 0 0
W
Reset00100000

Figure 16-8. SPI Status Register (SPIxS)

Table 16-5. SPIxS Register Field Descriptions

Field Description
7
SPRF
SPI Read Buffer Full Flag. SPRF is set at the completion of an SPI transfer to indicate that received data may be
read from the SPI data register (SPIxD). SPRF is cleared by reading SPRF while it is set, then reading SPIxD.
0 No data available in the receive data buffer
1 Data available in the receive data buffer
6 Reserved, should be cleared.
SPPR Prescaler Divisor SPPR Prescaler Divisor
0001 1005
0012 1016
0103 1107
0114 1118
SPR Rate Divisor SPR Rate Divisor
000 2 100 32
001 4 101 64
010 8 110 128
011 16 111 256