Am186™CC/CH/CU Microcontrollers User’s Manual
10-1
CHAPTER
10
PROGRAMMABLE TIMERS
10.1
OVERVIEW
There are three 16-bit programmable timers in the Am186CC/CH/CU microcontrollers.
Timers 0 and 1 are identical and may be used to generate periodic external signals or
waveforms or to count or time external events. Each of these two timers has an input and
an output pin. Timer 2 is an internal timer which can be used to prescale Timers 0 and 1
to provide longer time-out periods, or to generate DMA requests for the general-purpose
DMA channels (see Chapter 8, “DMA Controller”). All three timers can be programmed to
generate periodic interrupts.
The source clock for Timer 2 is one-fourth of the CPU clock frequency (every fourth CPU
clock tick). The source clock for Timers 0 and 1 can be the timer input pin, Timer 2, or one-
fourth of the CPU clock,.
The microcontroller also provides a pulse width demodulation (PWD) option for measuring
the Low state and High state durations of a toggling input signal.
10.2
BLOCK DIAGRAM
Figure 10-1 shows the block diagram for the programmable timers.
Figure 10-1
Programmable Timers Block Diagram
CPU, Memory, and Other Peripheral Devices
PCB Interface
Interrupt
DMA
TMROUT0
TMROUT1
Controller
Controller
INT7
Notes:
1. In PWD mode, the TMRIN0, TMRIN1 and INT7 pins can be used as PIOs. If INT7 is to be used as an external
interrupt in PWD mode, it must be programmed to use the shared interrupt channel (channel 14).
Timer 0
Timer 1
Timer 2
Timers
PWD bit
INT8/PWD
TMRIN0
TMRIN1
in SYSCON
register
CH12
CH13
0
0
0
1
1
1
CH0
Summary of Contents for Am186 CC
Page 1: ...Am186 CC CH CU Microcontrollers User s Manual Order 21914B...
Page 4: ...iv Am186 CC CH CU Microcontrollers User s Manual...
Page 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Page 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Page 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Page 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Page 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Page 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Page 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Page 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Page 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Page 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Page 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Page 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Page 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Page 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Page 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...