MC68711E20CFNE3 Datasheet, PDF (28/242 Pages) –

General Description
1.4.15 Port D
Pins PD5–PD0 can be used for general-purpose I/O signals. These pins alternately serve as the serial
communication interface (SCI) and serial peripheral interface (SPI) signals when those subsystems are
enabled.
• PD0 is the receive data input (RxD) signal for the SCI.
• PD1 is the transmit data output (TxD) signal for the SCI.
• PD5–PD2 are dedicated to the SPI:
– PD2 is the master in/slave out (MISO) signal.
– PD3 is the master out/slave in (MOSI) signal.
– PD4 is the serial clock (SCK) signal.
– PD5 is the slave select (SS) input.
1.4.16 Port E
Use port E for general-purpose or analog-to-digital (A/D) inputs.
CAUTION
If high accuracy is required for A/D conversions, avoid reading port E during
sampling, as small disturbances can reduce the accuracy of that result.
M68HC11E Family Data Sheet, Rev. 5.1
28
Freescale Semiconductor