© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
User manual
Rev. 01 — 15 August 2005
118
Philips Semiconductors
UM10139
Volume 1
Chapter 10: UART1
[1]
Values in the row represent decimal equivalent of a 16 bit long content (DLM:DLL).
[2]
Values in the row represent hex equivalent of a 16 bit long content (DLM:DLL).
[3]
Refers to the percent error between desired and actual baudrate.
10.3.6 UART1 Interrupt Enable Register (U1IER - 0xE001 0004, when
DLAB = 0)
The U1IER is used to enable UART1 interrupt sources.
7200
00AE
174
0.2240
124
5/(5+2)
0.0064
9600
0082
130
0.1600
93
5/(5+2)
0.0064
19200
0041
65
0.1600
31
10/(10+11)
0.0064
38400
0021
33
1.3760
12
7/(7+12)
0.0594
56000
0021
22
1.4400
13
7/(7+5)
0.0160
57600
0016
22
1.3760
19
7/(7+1)
0.0594
112000
000B
11
1.4400
6
7/(7+6)
0.1600
115200
000B
11
1.3760
4
7/(7+12)
0.0594
224000
0006
6
7.5200
3
7/(7+6)
0.1600
448000
0003
3
7.5200
2
5/(5+2)
0.3520
Table 119: Baudrates available when using 20 MHz peripheral clock (PCLK = 20 MHz)
Desired
baudrate
MULVAL = 0 DIVADDVAL = 0
Optimal MULVAL & DIVADDVAL
U1DLM:U1DLL
% error
[3]
U1DLM:U1DLL
dec
[1]
Fractional
pre-scaler value
MULDIV
DIVADDVAL
% error
[3]
hex
[2]
dec
[1]
Table 120: UART1 Interrupt Enable Register (U1IER - address 0xE001 0004, when DLAB = 0)
bit description
Bit
Symbol
Value
Description
Reset value
0
RBR
Interrupt
Enable
0
U1IER[0] enables the Receive Data Available
interrupt for UART1. It also controls the Character
Receive Time-out interrupt.
0
Disable the RDA interrupts.
1
Enable the RDA interrupts.
1
THRE
Interrupt
Enable
0
U1IER[1] enables the THRE interrupt for UART1.
The status of this interrupt can be read from
U1LSR[5].
0
Disable the THRE interrupts.
1
Enable the THRE interrupts.
2
RX Line
Interrupt
Enable
0
U1IER[2] enables the UART1 RX line status
interrupts. The status of this interrupt can be read
from U1LSR[4:1].
0
Disable the RX line status interrupts.
1
Enable the RX line status interrupts.
3
Modem
Status
Interrupt
Enable
0
U1IER[3] enables the modem interrupt. The status
of this interrupt can be read from U1MSR[3:0].
0
Disable the modem interrupt.
1
Enable the modem interrupt.