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Rev. 1.00
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Standard 8051 8-Bit Flash MCU
HT85F2260/HT85F2270/HT85F2280
UART Serial Interfaces – UART0 and UART1
S1RELL Register – UART1 Reload Low Register
SFR Address: 9Dh
Bit
7
6
5
4
3
2
1
0
Name
S1REL.7
S1REL.6
S1REL.�
S1REL.4
S1REL.3
S1REL.�
S1REL.1
S1REL.0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
S1RELH Register – UART1 Reload High Register
SFR Address: BBh
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
—
—
S1REL.9
S1REL.8
R/W
—
—
—
—
—
—
R/W
R/W
POR
—
—
—
—
—
—
1
1
The UART1 Reload registers, S1RELL and S1RELH, are used to setup the UART1 baud rate
generation. The UART1 baud rate setup range is 10-bit wide, consisting of 8 bits in S1RELL and 2
bits in S1RELH.
SPPRE Register – UART Clock Prescaler Register
SFR Address: A5h
Bit
7
6
5
4
3
2
1
0
Name
—
—
—
—
S1PRE1
S1PRE0
S0PRE1
S0PRE0
R/W
—
—
—
—
R/W
R/W
R/W
R/W
POR
—
—
—
—
1
1
1
1
Bit 7~4
Unimplemented, read as “0”
Bit 3~2
S1PRE1,
S1PRE0:
UART 1 Reload Counter Clock Select
00: f
SYS
/12
01: f
SYS
/6
10: f
SYS
/4
11: f
SYS
Bit 1~0
S0PRE1,
S0PRE0:
UART 0 Reload Counter Clock Select
00: f
SYS
/12
01: f
SYS
/6
10: f
SYS
/4
11: f
SYS