Allwinner A20 - Page 613

A20 User Manual (Revision 1.2) Copyright © 2013 Allwinner Technology Co., Ltd. All Rights Reserved. Page 613 / 812
Offset: 0x04
Register Name: UART_IER
Default Value: 0x0000_0000
Bit
Read/Write
Default
Description
Data Available Interrupt and the Character Timeout Interrupt
(if in FIFO mode and FIFOs enabled). These are the second
highest priority interrupts.
0: Disable
1: Enable
6.4.4.6. UART INTERRUPT IDENTITY REGISTER
Offset: 0x08
Register Name: UART_IIR
Default Value: 0x0000_0000
Bit
Read/Write
Default
Description
31:8
/
/
/
7:6
R
0
FEFLAG
FIFOs Enable Flag
This is used to indicate whether the FIFOs are enabled or
disabled.
00: Disable
11: Enable
5:4
/
/
/
3:0
R
0x1
IID
Interrupt ID
This indicates the highest priority pending interrupt which can
be one of the following types:
0000: modem status
0001: no interrupt pending
0010: THR empty
0100: received data available
0110: receiver line status
0111: busy detect
1100: character timeout
Bit 3 indicates an interrupt can only occur when the FIFOs
are enabled and used to distinguish a Character Timeout
condition interrupt.