Table of Contents
Advertisement
4.8 Keypad Signals
4.8.1 Column Strobes (COL[7:0])
These are general-purpose I/O pins used as keypad column strobes. They are open-
drain selectable in software. The default state at reset is general-purpose input.
4.8.2 Row Senses (ROW[7:0])
These are general-purpose I/O pins used as keypad row senses. The default state at
reset is general-purpose input. On-chip 47-Kbyte pull-up resistors are connected to
these pins.
4.9 UART Module Signals
The following signals are used by the UART module for data and clock signals. They
are also shared for provision of internal processor status. See SECTION 11 UNIVER-
SAL ASYNCHRONOUS RECEIVER/TRANSMITTER MODULE for more information
on these signals. See 7.7 EIM Configuration Register for provision of internal status
signal operation.
4.9.1 Receive Data (RxD0, RxD1)
These signals are used for receiver data input for UART channels 0 and 1, respec-
tively. Data is sampled on the rising edge of the clock source, with the least significant
bit received first.
RxD0 is used to provide the PSTAT1 internal status signal when the PSTEN bit in the
EIM configuration register is set. In this case it operates as an active-high PSTAT1
output.
RxD1 is used to provide the TSIZ1 internal status signal when the SZEN bit in the
EIM configuration register is set. In this case it operates as an active-high TSIZ1 out-
put.
4.9.2 Transmit Data (TxD0, TxD1)
These signals are used for transmit data output for UART channels 0 and 1, respec-
tively. The output is held high ("mark" condition) when the transmitter is disabled, idle,
or operating in the local loopback mode. Data is shifted out at the falling edge of the
clock source with the least significant bit transmitted first.
TxD0 is used to provide the PSTAT0 internal status signal when the PSTEN bit in the
EIM configuration register is set. In this case it operates as an active-high PSTAT0
output.
TxD1 is used to provide the TSIZ0 internal status signal when the SZEN bit in the
EIM configuration register is set. In this case it operates as an active-high TSIZ0 out-
put.
MMC2001
REFERENCE MANUAL
Freescale Semiconductor, Inc.
SIGNAL DESCRIPTIONS
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA
4-7
Advertisement
Table of Contents
