
W83977F/ W83977AF
PRELIMINARY
Publication Release Date: March 1998
- 53 -
Revision 0.58
4.2 Set0-Legacy/Advanced IR Control and Status Registers
Address Offset
0
1
2
3
4
5
6
7
Register Name
RBR/TBR
ICR
ISR/UFR
UCR/SSR
HCR
USR
HSR
UDR/ESCR
Register Description
Receiver/Transmitter Buffer Registers
Interrupt Control Register
Interrupt Status or IR FIFO Control Register
IR Control or Sets Select Register
Handshake Control Register
IR Status Register
Handshake Status Register
User Defined Register
4.2.1 Set0.Reg0 - Receiver/Transmitter Buffer Registers (RBR/TBR) (Read/Write)
Receiver Buffer Register is read only and Transmitter Buffer Register is write only. When operate in
the PIO mode, the port is used to Receive/Transmit 8-bit data.
When function as a legacy IR, this port only supports PIO mode. If set in the advanced IR mode and
configured as MIR/FIR/Remote IR, this port can support DMA transmission. Two DMA channels can
be used simultaneously, one for TX DMA and the other for RX DMA. Therefore, single DMA channel
is also supported when set the bit of D_CHSW (DMA Channel Swap, in Set2.Reg2.Bit3) and the
TX/RX DMA channel is swapped. Note that two DMA channel can be defined in configure register
CR2A which selects DMA channel or disables DMA channel. If only RX DMA channel is enabled
while TX DMA channel is disabled, then the single DMA channel will be selected.
4.2.2 Set0.Reg1 - Interrupt Control Register (ICR)
Mode
Legacy IR
Advanced IR
B7
0
B6
0
B5
0
B4
0
B3
0
0
B2
B1
B0
EUSRI
EUSRI/
TXURI
ETBREI
ETBREI
ERDRI
ERBRI
ETMRI
EFSFI
ETXTHI
EDMAI
The advanced IR functions including Advanced SIR/ASK-IR, MIR, FIR, or Remote IR are described
as follows.
Bit 7:
Legacy IR Mode:
Not used. A read will return 0.
Advanced IR Mode:
ETMRI - Enable Timer Interrupt
A write to 1 will enable timer interrupt.
Legacy IR Mode:
Not used. A read will return 0.
MIR, FIR mode:
EFSFI - Enable Frame Status FIFO Interrupt
A write to 1 will enable frame status FIFO interrupt.
Advanced SIR/ASK-IR, Remote IR:
Not used.
Legacy IR Mode:
Not used. A read will return 0.
Advanced SIR/ASK-IR, MIR, FIR, Remote IR:
ETXTHI - Enable Transmitter Threshold Interrupt
A write to 1 will enable transmitter threshold interrupt.
Bit 6:
Bit 5: