MC68HC812A4 Datasheet, PDF (176/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Standard Timer Module
12.7 External Pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .203
12.7.1 Input Capture/Output Compare Pins . . . . . . . . . . . . . . . . .203
12.7.2 Pulse Accumulator Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . .203
12.8 Background Debug Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . .204
12.9 Low-Power Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204
12.9.1 Run Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204
12.9.2 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204
12.9.3 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205
12.10 Interrupt Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205
12.11 General-Purpose I/O Ports . . . . . . . . . . . . . . . . . . . . . . . . . . .205
12.11.1 Timer Port Data Register . . . . . . . . . . . . . . . . . . . . . . . . . .206
12.11.2 Timer Port Data Direction Register . . . . . . . . . . . . . . . . . .207
12.11.3 Data Direction Register for Timer Port . . . . . . . . . . . . . . . .208
12.12 Using the Output Compare Function to Generate
a Square Wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .209
12.12.1 Sample Calculation to Obtain Period Counts . . . . . . . . . . .209
12.12.2 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .210
12.12.3 Code Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .210
12.2 Introduction
The standard timer module is a 16-bit, 8-channel timer with:
• Input capture
• Output compare
• Pulse accumulator functions
A block diagram is given in Figure 12-1 and a summary of the
input/oputput (I/O) registers is shown in Figure 12-2.
MC68HC812A4 — Rev. 3.0
176
Standard Timer Module
Advance Information
MOTOROLA