MMC2001
UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER MODULE
MOTOROLA
REFERENCE MANUAL
11-15
RTSD — RTS Delta
When set, this bit indicates that the RTS pin changed state. It generates a maskable
interrupt. In STOP mode, RTS assertion sets this bit to wake the CPU. The current
state of the RTS pin is available in the RTSS bit. The RTSD interrupt is cleared by
writing a one to this bit.
0 =
RTS pin did not change state since last cleared
1 =
RTS pin changed state
At reset, this bit is cleared to zero.
11.4.7 UART Test Register (UTS)
The UART test register is a read/write register. Unimplemented bits always return
zero when read. This register contains miscellaneous bits to control test features of
the UART block.
Figure 11-8 UART Test Register
FRC PERR — Force Parity Error
When set, this bit forces the transmitter to generate a parity error if parity is enabled.
This bit is provided for system debugging.
0 =
Generate normal parity
1 =
Generate inverted parity (error)
At reset, this bit is cleared to zero.
LOOP — Loop TX and RX for Test
This bit controls loopback for test purposes. While this bit is high, the receiver input is
internally connected to the transmitter and ignores the RxD pin. The transmitter is
unaffected by this bit. This loopback operates to connect the data on the TxD pin
directly to the voting logic. If infrared mode is enabled (IR_EN is active), the effect of
activating this bit is to put an IR-formatted bit stream into the voting logic, which will
yield odd results. Do not use this loopback if IR_EN is active.
0 =
Normal receiver operation
1 =
Internal connect transmitter output to receiver input
At reset, this bit is cleared to zero.
LOOP IR — Loop TX and RX for IR Test
This bit controls a loopback from transmitter to receiver in the infrared interface.
0 =
No IR loop
1 =
Connect IR transmit to IR receiver
At reset, this bit is cleared to zero.
U0TS — UART0 Test Register
10009088
U1TS — UART1 Test Register
1000A088
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
0
0
FRC
PERR
LOOP
0
LOOP
IR
0
0
0
0
0
0
0
0
0
0
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Freescale Semiconductor,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
nc.
..