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Philips Semiconductors
Preliminary User Manual
LPC2119/2129/2292/2294
ARM-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
2
Tx 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=’h1)
01: trigger level 1 (default=’h4)
10: trigger level 2 (default=’h8)
11: trigger level 3 (default=’he)
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