C505_9708 SIEMENS [Siemens Semiconductor Group], C505_9708 Datasheet - Page 80

• Manufacturer Part Number: C505_9708
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Special Function Register TMOD (Address 89 H )
Bit
GATE
C/T
M1
M0
Semiconductor Group
Bit No.
89 H
Function
Gating control
When set, timer/counter "x" is enabled only while "INT x" pin is high and "TRx"
control bit is set.
When cleared timer "x" is enabled whenever "TRx" control bit is set.
Counter or timer select bit
Set for counter operation (input from "Tx" input pin).
Cleared for timer operation (input from internal system clock).
Mode select bits
M1
0
0
1
1
MSB
Gate
7
Timer 1 Control
M0
0
1
0
1
C/T
6
M1
5
Function
8-bit timer/counter:
"THx" operates as 8-bit timer/counter
"TLx" serves as 5-bit prescaler
16-bit timer/counter.
"THx" and "TLx" are cascaded; there is no prescaler
8-bit auto-reload timer/counter.
"THx" holds a value which is to be reloaded into "TLx" each
time it overflows
Timer 0 :
TL0 is an 8-bit timer/counter controlled by the standard
timer 0 control bits. TH0 is an 8-bit timer only controlled by
timer 1 control bits.
Timer 1 :
Timer/counter 1 stops
M0
4
6-18
Gate
3
On-Chip Peripheral Components
Timer 0 Control
C/T
2
M1
1
LSB
M0
0
Reset Value : 00 H
C505 / C505C
TMOD
1997-08-01