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Device Specifications
Semiconductor Group
236
Timer/Counters
The SAB 80C515 contains three 16-bit timers/counters which are useful in many applications
for timing and counting. The input clock for each timer/counter is 1/12 of the oscillator frequency
in the timer operation or can be taken from an external clock source for the counter operation
(maximum count rate is 1/24 of the oscillator frequency).
– Timer/Counter 0 and 1
These timers/counters can operate in four modes:
Mode 0: 8-bit timer/counter with 32:1 prescaler
Mode 1: 16-bit timer/counter
Mode 2: 8-bit timer/counter with 8-bit auto-reload
Mode 3: Timer/counter 0 is configured as one 8-bit timer/counter and one 8-bit timer;
Timer/counter 1 in this mode holds its count.
External inputs INT0 and INT1 can be programmed to function as a gate for
timer/counters 0 and 1 to facilitate pulse width measurements.
– Timer/Counter 2
Timer/counter 2 of the SAB 80C515 is a 16-bit timer/counter with several additional features. It
offers a 2:1 prescaler, a selectable gate function, and compare, capture and reload functions.
Corresponding to the 16-bit timer register there are four 16-bit capture/compare registers, one
of them can be used to perform a 16-bit reload on a timer overflow or external event. Each of
these registers corresponds to a pin of port 1 for capture input/compare output.
Figure 3 shows a block diagram of timer/counter 2.
Reload
A 16-bit reload can be performed with the 16-bit CRC register consisting of CRCL and CRCH.
There are two modes from which to select:
Mode 0: Reload is caused by a timer 2 overflow (auto-reload).
Mode 1: Reload is caused in response to a negative transition at pin T2EX (P1.5), which
can also request an interrupt.
Capture
This feature permits saving the actual timer/counter contents into a selected register
upon an external event or a software write operation. Two modes are provided to latch
the current 16-bit value in timer 2 registers TL2 and TH2 into a dedicated capture register:
Mode 0: Capture is performed in response to a transition at the corresponding port 1 pins
CC0 to CC3.
Mode 1: Write operation into the low-order byte of the dedicated capture register causes
the timer 2 contents to be latched into this register.
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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 ...