XR16M770
25
REV. 1.0.2
1.62V TO 3.63V HIGH PERFORMANCE UART WITH 64-BYTE FIFO
4.0 INTERNAL REGISTER DESCRIPTIONS
4.1
Receive Holding Register (RHR) - Read- Only
4.2
Transmit Holding Register (THR) - Write-Only
Baud Rate Generator Divisor
0 0 0
DREV
RD
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
LCR[7] = 1
LCR
≠0xBF
DLL= 0x00
DLM= 0x00
0 0 1
DVID
RD
0
1
0
1
0 0 0
DLL
RD/WR
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
LCR[7] = 1
LCR
≠0xBF
DLD[7:6]
0 0 1
DLM
RD/WR
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
0 1 0
DLD
RD/WR
BRG
select
Enable
Indepen-
dent
BRG
4X Mode 8X Mode
Bit-3
Bit-2
Bit-1
Bit-0
LCR[7] = 1
LCR
≠0xBF
EFR[4] = 1
Enhanced Registers
0 0 0
FC
RD
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
LCR=0XBF
0 0 0
TRIG
WR
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
0 0 1
FCTR RD/WR RX/TX
select
Swap
SCR
trigger
mode
bit-1
trigger
mode
bit-0
RS485
interrupt
mode
invert
RX IR
RTS
delay
bit-1
RTS
delay
bit-0
0 1 0
EFR
RD/WR
Auto
CTS#
Enable
Auto
RTS#
Enable
Special
Char
Select
Enable
IER [7:4],
ISR [5:4],
FCR[5:3],
MCR[7:5],
DLD
Soft-
ware
Flow
Cntl
Bit-3
Soft-
ware
Flow
Cntl
Bit-2
Soft-
ware
Flow
Cntl
Bit-1
Soft-
ware
Flow
Cntl
Bit-0
1 0 0
XON1 RD/WR
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
1 0 1
XON2 RD/WR
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
1 1 0
XOFF1 RD/WR
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
1 1 1
XOFF2 RD/WR
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
TABLE 7: INTERNAL REGISTERS DESCRIPTION. SHADED BITS ARE ENABLED WHEN EFR BIT-4=1
A
A2-A0
REG
NAME
READ/
WRITE
BIT-7
BIT-6
BIT-5
BIT-4
BIT-3
BIT-2
BIT-1
BIT-0
COMMENT