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MS51
Dec. 17, 2019
Page
49
of 316
Rev 1.01
M
S51
SE
RIES
TE
CHNICA
L REF
ERE
N
CE MA
NU
A
L
TMOD
– Timer 0 and 1 Mode
Regiser
Address
Reset Value
RCTRIM1
89H, all pages
0000_0000b
7
6
5
4
3
2
1
0
GATE
C/T
̅
M1
M0
GATE
C/T
̅
M1
M0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Bit
Name
Description
7
GATE
Timer 1 gate control
0 = Timer 1 will clock when TR1 is 1 regardless of
INT1
̅̅̅̅̅̅̅
logic level.
1 = Timer 1 will clock only when TR1 is 1 and
INT1
̅̅̅̅̅̅̅
is logic 1.
6
C/T
̅
Timer 1 Counter/Timer select
0 = Timer 1 is incremented by internal system clock.
1 = Timer 1 is incremented by the falling edge of the external pin T1.
5
M1
Timer 1 mode select
M1
M0
Timer 1 Mode
0
0
Mode 0: 13-bit Timer/Counter
0
1
Mode 1: 16-bit Timer/Counter
1
0
Mode 2: 8-bit Timer/Counter with auto-reload from TH1
1
1
Mode 3: Timer 1 halted
4
M0
3
GATE
Timer 0 gate control
0 = Timer 0 will clock when TR0 is 1 regardless of
INT0
̅̅̅̅̅̅̅
logic level.
1 = Timer 0 will clock only when TR0 is 1 and
INT0
̅̅̅̅̅̅̅
is logic 1.
2
C/T
̅
Timer 0 Counter/Timer select
0 = Timer 0 is incremented by internal system clock.
1 = Timer 0 is incremented by the falling edge of the external pin T0.
1
M1
Timer 0 mode select
M1
M0
Timer 0 Mode
0
0
Mode 0: 13-bit Timer/Counter
0
1
Mode 1: 16-bit Timer/Counter
1
0
Mode 2: 8-bit Timer/Counter with auto-reload from TH0
1
1
Mode 3: TL0 as a 8-bit Timer/Counter and TH0 as a 8-bit Timer
0
M0