
Semiconductor Group
67
On-Chip Peripheral Components
Figure 7-20
Special Function Register TMOD (Address 89H)
Timer/counter 0/1 mode control register.
Bit
Symbol
Gate
Gating control.
When set, timer/counter "x" is enabled only while "INTx" pin is high and
"TRx" control bit is set.
When cleared timer "x" is enabled whenever "TRx" control bit is set.
C/T
Counter or timer select bit.
Set for counter operation (input from "Tx" input pin).
Cleared for timer operation (input from internal system clock).
M1
M0
0
0
8-bit timer/counter
"THx" operates as 8-bit timer/counter
"TLx" serves as 5-bit prescaler.
0
1
16-bit timer/counter.
"THx" and "TLx" are cascaded; there is no prescaler.
1
0
8-bit auto-reload timer/counter.
"THx" holds a value which is to be reloaded into "TLx" each time it
overflows.
1
1
Timer 0:
TL0 is an 8-bit timer/counter controlled by the standard timer 0 control
bits. TH00 is an 8-bit timer only controlled by timer 1 control bits.
1
1
Timer 1:
Timer/counter 1 stops
GATE
C/T
M1
M0
GATE
C/T
M1
M0
89H
TMOD
Timer 1
Timer 0
*
Summary of Contents for SAB 80515 Series
Page 9: ...Semiconductor Group 9 Introduction Figure 1 2 Block Diagram ...
Page 12: ...Semiconductor Group 12 Fundamental Structure Figure 2 1 Detailed Block Diagram ...
Page 18: ...Semiconductor Group 18 Central Processing Unit Figure 3 1 Fetch Execute Sequence ...
Page 73: ...Semiconductor Group 73 On Chip Peripheral Components Figure 7 25 A D Converter Block Diagram ...
Page 83: ...Semiconductor Group 83 On Chip Peripheral Components Figure 7 33 a Timer 2 Block Diagram ...
Page 215: ...Device Specifications Semiconductor Group 215 ...
Page 217: ...Device Specifications Semiconductor Group 217 Pin Configuration P LCC 68 ...
Page 219: ...Device Specifications Semiconductor Group 219 Logic Symbol ...
Page 226: ...Device Specifications Semiconductor Group 226 Figure 1 Block Diagram ...
Page 229: ...Device Specifications Semiconductor Group 229 Figure 2 Memory Address Spaces ...
Page 239: ...Device Specifications Semiconductor Group 239 Figure 4 Block Diagram of the A D Converter ...
Page 241: ...Device Specifications Semiconductor Group 241 Figure 5 Interrupt Request Sources ...
Page 242: ...Device Specifications Semiconductor Group 242 Figure 6 Interrupt Priority Level Structure ...