MC68HC08AS32A Datasheet, PDF (165/296 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Input/Output (I/O) Ports
Port E
12.6 Port E
Port E is an 8-bit special-function port that shares two of its pins with the timer
interface module (TIM), two of its pins with the serial communications interface
module (SCI), and four of its pins with the serial peripheral interface module (SPI).
12.6.1 Port E Data Register
The port E data register contains a data latch for each of the eight port E pins.
Address: $0008
Read:
Write:
Bit 7
PTE7
6
PTE6
5
PTE5
4
PTE4
3
PTE3
2
PTE2
1
PTE1
Bit 0
PTE0
Reset:
Unaffected by reset
Alternate
Function:
SPSCK
MOSI
MISO
SS
TCH1
TCH0
RxD
TxD
Figure 12-14. Port E Data Register (PTE)
NOTE:
PTE[7:0] — Port E Data Bits
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.
SPSCK — SPI Serial Clock Bit
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.
MOSI — Master Out/Slave In Bit
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.
(See 15.13.1 SPI Control Register.)
MISO — Master In/Slave Out Bit
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 15.13.1 SPI Control
Register.)
SS — Slave Select Bit
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 15.12.4 SS (Slave
Select).) When the SPI is enabled as a slave, the DDRE4 bit in data direction
register E (DDRE) has no effect on the PTE4/SS pin.
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
MC68HC08AS32A — Rev. 1
MOTOROLA
Input/Output (I/O) Ports
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Data Sheet
165