9-17
TIMER/COUNTER UNIT
9.3.2 Synchronization and Maximum Frequency
All timer inputs are latched and synchronized with the CPU clock. Because of the internal logic
required to synchronize the external signals, and the multiplexing of the counter element, the
Timer/Counter Unit can operate only up to ¼ of the CLKOUT frequency. Clocking at greater fre-
quencies will result in missed clocks.
9.3.2.1 Timer/Counter Unit Application Examples
The following examples are possible applications of the Timer/Counter Unit. They include a real-
time clock, a square wave generator and a digital one-shot.
9.3.3 Real-Time Clock
Example 9-1 contains sample code to configure Timer 2 to generate an interrupt request every 10
milliseconds. The CPU then increments memory-based clock variables.
9.3.4 Square-Wave Generator
A square-wave generator can be useful to act as a system clock tick. Example 9-2 illustrates how
to configure Timer 1 to operate this way.
9.3.5 Digital One-Shot
Example 9-3 configures Timer 1 to act as a digital one-shot.
Содержание 80C186EA
Страница 1: ...80C186EA 80C188EA Microprocessor User s Manual...
Страница 2: ...80C186EA 80C188EA Microprocessor User s Manual 1995...
Страница 19: ......
Страница 20: ...1 Introduction...
Страница 21: ......
Страница 28: ...2 Overview of the 80C186 Family Architecture...
Страница 29: ......
Страница 79: ......
Страница 80: ...3 Bus Interface Unit...
Страница 81: ......
Страница 129: ......
Страница 130: ...4 Peripheral Control Block...
Страница 131: ......
Страница 139: ......
Страница 140: ...5 ClockGenerationand Power Management...
Страница 141: ......
Страница 165: ......
Страница 166: ...6 Chip Select Unit...
Страница 167: ......
Страница 190: ...7 Refresh Control Unit...
Страница 191: ......
Страница 205: ......
Страница 206: ...8 Interrupt Control Unit...
Страница 207: ......
Страница 239: ...INTERRUPT CONTROL UNIT 8 32...
Страница 240: ...9 Timer Counter Unit...
Страница 241: ......
Страница 265: ......
Страница 266: ...10 Direct Memory Access Unit...
Страница 267: ......
Страница 295: ...DIRECT MEMORY ACCESS UNIT 10 28...
Страница 296: ...11 Math Coprocessing...
Страница 297: ......
Страница 314: ...12 ONCE Mode...
Страница 315: ......
Страница 318: ...A 80C186 Instruction Set Additions and Extensions...
Страница 319: ......
Страница 330: ...B Input Synchronization...
Страница 331: ......
Страница 334: ...C Instruction Set Descriptions...
Страница 335: ......
Страница 383: ...INSTRUCTION SET DESCRIPTIONS C 48...
Страница 384: ...D Instruction Set Opcodes and Clock Cycles...
Страница 385: ......
Страница 408: ...Index...
Страница 409: ......