Philips LPC2129 - Table 94: UART1 FCR Bit Descriptions (U1 FCR - 0 Xe0010008)

UART1 158 May 03, 2004
Philips Semiconductors Preliminary User Manual
LPC2119/2129/2194/2292/2294ARM-based Microcontroller
UART1 FIFO Control Register (U1FCR - 0xE0010008)
The U1FCR controls the operation of the UART1 Rx and Tx FIFOs.
Table 95: UART1 FCR Bit Descriptions (U1FCR - 0xE0010008)
U1FCR Function Description
Reset
Value
0 FIFO Enable
Active high enable for both UART1 Rx and Tx FIFOs and U1FCR7:1 access. This bit
must be set for proper UART1 operation. Any transition on this bit will automatically clear
the UART1 FIFOs.
0
1 Rx FIFO Reset
Writing a logic 1 to U1FCR1 will clear all bytes in UART1 Rx FIFO and reset the pointer
logic. This bit is self-clearing.
0
2Tx FIFO Reset
Writing a logic 1 to U1FCR2 will clear all bytes in UART1 Tx FIFO and reset the pointer
logic. This bit is self-clearing.
0
5:3 Reserved
Reserved, user software should not write ones to reserved bits. The value read from a
reserved bit is not defined.
NA
7:6
Rx Trigger Level
Select
00: trigger level 0 (default=1 character or 0x01h)
01: trigger level 1 (default=4 characters or 0x04h)
10: trigger level 2 (default=8 characters or 0x08h)
11: trigger level 3 (default=14 characters or 0x0eh)
These two bits determine how many receiver UART1 FIFO characters must be written
before an interrupt is activated. The four trigger levels are defined by the user at
compilation allowing the user to tune the trigger levels to the FIFO depths chosen.
0