mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 521

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

12.3.2.2
Read: Anytime
Write: Anytime; writes to the reserved bits have no effect
Freescale Semiconductor
MODFEN
BIDIROE
SPISWAI
Reset
SPC0
Field
4
3
1
0
W
R
Mode Fault Enable Bit — This bit allows the MODF failure to be detected. If the SPI is in master mode and
MODFEN is cleared, then the SS port pin is not used by the SPI. In slave mode, the SS is available only as an
input regardless of the value of MODFEN. For an overview on the impact of the MODFEN bit on the SS port pin
configuration, refer to
force the SPI system into idle state.
0 SS port pin is not used by the SPI.
1 SS port pin with MODF feature.
Output Enable in the Bidirectional Mode of Operation — This bit controls the MOSI and MISO output buffer
of the SPI, when in bidirectional mode of operation (SPC0 is set). In master mode, this bit controls the output
buffer of the MOSI port, in slave mode it controls the output buffer of the MISO port. In master mode, with SPC0
set, a change of this bit will abort a transmission in progress and force the SPI into idle state.
0 Output buffer disabled.
1 Output buffer enabled.
SPI Stop in Wait Mode Bit — This bit is used for power conservation while in wait mode.
0 SPI clock operates normally in wait mode.
1 Stop SPI clock generation when in wait mode.
Serial Pin Control Bit 0 — This bit enables bidirectional pin configurations as shown in
mode, a change of this bit will abort a transmission in progress and force the SPI system into idle state.
SPI Control Register 2 (SPICR2)
0
0
7
MODFEN
= Unimplemented or Reserved
0
0
1
1
0
0
6
SSOE
Figure 12-4. SPI Control Register 2 (SPICR2)
Table
0
1
0
1
Table 12-2. SS Input / Output Selection
Table 12-3. SPICR2 Field Descriptions
MC9S12XDP512 Data Sheet, Rev. 2.17
12-4. In master mode, a change of this bit will abort a transmission in progress and
0
0
5
SS input with MODF feature
SS is slave select output
MODFEN
SS not used by SPI
SS not used by SPI
Master Mode
0
4
Description
BIDIROE
0
3
Chapter 12 Serial Peripheral Interface (S12SPIV4)
0
0
2
Slave Mode
SS input
SS input
SS input
SS input
SPISWAI
Table
0
1
12-4. In master
SPC0
0
0
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