mc68hc908as60 Freescale Semiconductor, Inc, mc68hc908as60 Datasheet - Page 282

• Manufacturer Part Number: mc68hc908as60
• Description: Mc68hc908as60 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Serial Peripheral Interface (SPI)
18.13.5 V
18.14 I/O Registers
Technical Data
SS
(Clock Ground)
The CPU can always read the state of the SS pin by configuring the
appropriate pin as an input and reading the data register. See
Table
V
for the port output buffers. To reduce the ground return path loop and
minimize radio frequency (RF) emissions, connect the ground pin of the
slave to the V
Three registers control and monitor SPI operation:
X = Don’t care
SPE SPMSTR MODFEN
SS
0
1
1
1
1. SPI control register (SPCR, $0010)
2. SPI status and control register (SPSCR, $0011)
3. SPI data register (SPDR, $0012)
Freescale Semiconductor, Inc.
is the ground return for the serial clock pin, SPSCK, and the ground
For More Information On This Product,
18-4.
X
0
1
1
Serial Peripheral Interface (SPI)
Go to: www.freescale.com
SS
pin.
X
X
0
1
Table 18-4. SPI Configuration
Master without MODF
SPI Configuration
Master with MODF
Not enabled
Slave
MC68HC908AS60 — Rev. 1.0
General-purpose I/O;
General-purpose I/O;
State of SS Logic
SS ignored by SPI
SS ignored by SPI
Input-only to SPI
Input-only to SPI