mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 280

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 9 Serial Peripheral Interface (SPIV3)
9.3.2.2
Read: anytime
Write: anytime; writes to the reserved bits have no effect
280
MODFEN
BIDIROE
SPISWAI
Reset
SPC0
Field
4
3
1
0
W
R
Bidirectional
Bidirectional
Pin Mode
Normal
Normal
Mode Fault Enable Bit — This bit allows the MODF failure being 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
= Unimplemented or Reserved
0
0
6
SPC0
0
1
0
1
Table
Figure 9-4. SPI Control Register 2 (SPICR2)
Table 9-5. Bidirectional Pin Configurations
Table 9-4. SPICR2 Field Descriptions
9-3. In master mode, a change of this bit will abort a transmission in progress and
BIDIROE
MC9S12E256 Data Sheet, Rev. 1.08
0
0
5
X
1
X
1
0
0
Master Mode of Operation
Slave Mode of Operation
MODFEN
MISO not used by SPI
0
4
Description
Slave Out
Master In
Slave I/O
Slave In
MISO
BIDIROE
3
0
0
0
2
MOSI not used by SPI
Master Out
Master I/O
Master In
Slave In
MOSI
SPISWAI
Freescale Semiconductor
Table
0
1
9-5. In master
SPC0
0
0