UART/IrDA Control and Status Registers
12-58
Table 12–48. Supplementary Control Register (SCR)
Bit
Name
Value
Function
R/W
Reset
Value
7
RX_TRIG_GRANU1
0
Disables the granularity of 1 for trigger
RX level
R/W
0
1
Enables the granularity of 1 for trigger
RX level
6
TX_TRIG_GRANU1
0
Disables the granularity of 1 for trigger
TX level
R/W
0
1
Enables the granularity of 1 for trigger
TX level
5
DSR_IT
0
Disables DSR interrupt
R/W
0
1
Enables DSR interrupt
4
RX_CTS_DSR_WAKE_
UP_ENABLE
0
Disables the wake up interrupt and
clears SSR1
R/W
0
1
Waits for a falling edge of pins RX, CTS
or DSR to generate an interrupt
3
TX_EMPTY_CTL_IT
0
Normal mode for THR interrupt (see
Table 12–55)
R/W
0
1
The THR interrupt is generated when TX
FIFO and TX shift register are empty.
2–1
DMA_MODE_2
Used to specify the DMA mode valid if
SCR0 = 1
R/W
00
00
DMA mode 0 (no DMA)
01
DMA mode 1 (UART_nDMA_REQ0 in
TX, UART_nDMA_REQ1 in RX)
10
DMA mode 2 (UART_nDMA_REQ0 in
RX)
11
DMA mode 3 (UART_nDMA_REQ0 in
TX)
0
DMA_MODE_CTL
0
The DMA_MODE is set with FCR3.
R/W
0
1
The DMA_MODE is set with SCR2:1.
Note:
Bit 4 enables the wake-up interrupt, but this interrupt is not mapped on the IIR register. Therefore, when an interrupt
occurs and if there is no interrupt pending in IIR, SSR[1] must be checked. To clear the wake-up interrupt, SCR[4] must be
reset to 0.