
Chapter 25 Serial Peripheral Interface (S12SPIV5)
MC9S12XF - Family Reference Manual, Rev.1.19
Freescale Semiconductor
1107
Table 25-9. SPTEF Interrupt Flag Clearing Sequence
XFRW Bit
SPTEF Interrupt Flag Clearing Sequence
0
Read SPISR with SPTEF == 1 then
Write to SPIDRL (1)
1. Any write to SPIDRH or SPIDRL with SPTEF == 0 is effectively ignored.
1
Read SPISR with SPTEF == 1
then
Byte Write to SPIDRL
1(2)2. Data in SPIDRH is undened in this case.
or
Byte Write to SPIDRH
1(3)3. SPIDRH can be written repeatedly without any effect on SPTEF. SPTEF Flag is cleared only by
writing to SPIDRL after reading SPISR with SPTEF == 1.
or
Word Write to (SPIDRH:SPIDRL)
1