ML51/ML54/ML56
Sep. 01, 2020
Page
125
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Rev 2.00
ML
51
/ML
54
/ML
5
6 S
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TECHNI
CA
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F
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M
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ML51/M
L54
/M
L56
Series
Tec
hnical Reference
Manual
TCON
– Timer 0 and 1 Control
Register
SFR Address
Reset Value
TCON
88H, All pages, Bit-addressable
0000_0000b
7
6
5
4
3
2
1
0
TF1
TR1
TF0
TR0
IE1
IT1
IE0
IT0
R/W
R/W
R/W
R/W
R (level)
R/W (edge)
R/W
R (level)
R/W (edge)
R/W
Bit
Name
Description
[7]
TF1
Timer 1 Overflow Flag
This bit is set when Timer 1 overflows. It is automatically cleared by hardware when the
program executes the Timer 1 interrupt service routine. This bit can be set or cleared by
software.
[6]
TR1
Timer 1 Run Control
0 = Timer 1 Disabled. Clearing this bit will halt Timer 1 and the current count will be preserved in
TH1 and TL1.
1 = Timer 1 Enabled.
[5]
TF0
Timer 0 Overflow Flag
This bit is set when Timer 0 overflows. It is automatically cleared via hardware when the
program executes the Timer 0 interrupt service routine. This bit can be set or cleared by
software.
[4]
TR0
Timer 0 Run Control
0 = Timer 0 Disabled. Clearing this bit will halt Timer 0 and the current count will be preserved in
TH0 and TL0.
1 = Timer 0 Enabled.
[3]
IE1
External Interrupt 1 Edge Flag
If IT1 = 1 (falling edge trigger), this flag will be set by hardware when a falling edge is detected.
It remain set until cleared via software or cleared by hardware in the beginning of its interrupt
service routine.
If IT1 = 0 (low level trigger), this flag follows the inverse of the INT1
input signal’s logic level.
Software cannot control it.
[2]
IT1
External Interrupt 1 Type Select
This bit selects by which type that INT1 is triggered.
0 = INT1 is low level triggered.
1 = INT1 is falling edge triggered.
[1]
IE0
External Interrupt 0 Edge Flag
If IT0 = 1 (falling edge trigger), this flag will be set by hardware when a falling edge is detected.
It remain set until cleared via software or cleared by hardware in the beginning of its interrupt
service routine.
If IT0 = 0 (low level trigger), this flag follows the inverse of the INT0
input signal’s logic level.
Software cannot control it.
