
W83977F/ W83977AF
PRELIMINARY
Publication Release Date: March 1998
- 67 -
Revision 0.58
4.7 Set 5 - Flow control
and
IR control
and
Frame Status FIFO registers
Address Offset
0
1
2
3
4
5
6
7
Register Name
FCBLL
FCBHL
FC_MD
SSR
IRCFG1
FS_FO
RFRLFL
RFRLFH
Register Description
Flow Control Baud Rate Divisor Latch Register (Low Byte)
Flow Control Baud Rate Divisor Latch Register (High Byte)
Flow Control Mode Operation
Sets Select Register
Infrared Configure Register
Frame Status FIFO Register
Receiver Frame Length FIFO Low Byte
Receiver Frame Length FIFO High Byte
4.7.1 Set5.Reg0, 1 - Flow Control Baud Rate Divisor Latch Register (FCDLL/ FCDHL)
If flow control is enforced when UART switches mode from MIR/FIR to SIR, then the pre-programmed
baud rate of FCBLL/FCBHL are loaded into advanced baud rate divisor latch (ADBLL/ADBHL).
4.7.2 Set5.Reg2 - Flow Control Mode Operation (FC_MD)
These registers control flow control mode operation as shown in the following table.
Reg.
Bit 7
Bit 6
Bit 5
FC_MD
FC_MD2
FC_MD1
FC_MD0
Reset Value
0
0
0
Bit 4
-
0
Bit 3
FC_DSW
0
Bit 2
EN_FD
0
Bit 1
Bit 0
EN_FC
0
EN_BRFC
0
Bit 7~5
FC_MD2 - Flow Control Mode
When flow control is enforced, these bits will be loaded into AD_MD2~0 of advanced
HSR (Handshake Status Register). These three bits are defined as same as AD_MD2~0.
Reserved
, write 0.
FC_DSW - Flow Control DMA Channel Swap
A write to 1 allow user to swap DMA channel for transmitter or receiver when flow control
is enforced.
Bit 4:
Bit 3:
FC_DSW
0
1
Next Mode After Flow Control Occurred
Receiver Channel
Transmitter Channel
Bit 2:
EN_FD - Enable Flow DMA Control
A write to 1 enables UART to use DMA channel when flow control is enforced.
EN_BRFC - Enable Baud Rate Flow Control
A write to 1 enables FC_BLL/FC_BHL (Flow Control Baud Rate Divider Latch, in
Set5.Reg1~0) to be loaded into advanced baud rate divisor latch (ADBLL/ADBHL, in
Set2.Reg1~0).
EN_FC - Enable Flow Control
A write to 1 enables flow control function and bit 7~1 of this register.
Bit 1:
Bit 0: