MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 258

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Input/Output Ports
22.6 Port E
Port E is an 8-bit special function port that shares two of its pins with the timer interface module (TIMA),
two of its pins with the serial communications interface module (SCI), and four of its pins with the serial
peripheral interface module (SPI).
22.6.1 Port E Data Register
The port E data register contains a data latch for each of the eight port E pins.
PTE[7:0] — Port E Data Bits
SPSCK — SPI Serial Clock Bit
MOSI — Master Out/Slave In Bit
MISO — Master In/Slave Out Bit
SS — Slave Select Bit
258
PTE[7:0] are read/write, software programmable bits. Data direction of each port E pin is under the
control of the corresponding bit in data direction register E.
The PTE7/SPSCK pin is the serial clock input of an SPI slave module and serial clock output of an SPI
master module. When the SPE bit is clear, the PTE7/SPSCK pin is available for general-purpose I/O.
(See
The PTE6/MOSI pin is the master out/slave in terminal of the SPI module. When the SPE bit is clear,
the PTE6/MOSI pin is available for general-purpose I/O.
The PTE5/MISO pin is the master in/slave out terminal of the SPI module. When the SPI enable bit,
SPE, is clear, the SPI module is disabled, and the PTE5/MISO pin is available for general-purpose I/O.
(See
The PTE4/SS pin is the slave select input of the SPI module. When the SPE bit is clear, or when the
SPI master bit, SPMSTR, is set and MODFEN bit is low, the PTE4/SS pin is available for
general-purpose I/O. (See
bit in data direction register E (DDRE) has no effect on the PTE4/SS pin.
19.13.1 SPI Control
19.13.1 SPI Control
Alternative
Function:
Address:
Data direction register E (DDRE) does not affect the data direction of port
E pins that are being used by the SPI module. However, the DDRE bits
always determine whether reading port E returns the states of the latches
or the states of the pins. (See
Reset:
Read:
Write:
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
SPSCK
$0008
PTE7
Bit 7
Register).
Register).
19.12.4 SS (Slave
Figure 22-14. Port E Data Register (PTE)
PTE6
MOSI
6
PTE5
MISO
5
Table
Select)). When the SPI is enabled as a slave, the DDRF0
NOTE
Unaffected by Reset
PTE4
SS
22-5).
4
TACH1
PTE3
3
TACH0
PTE2
2
PTE1
RxD
1
Freescale Semiconductor
PTE0
Bit 0
TxD