AN2690 Freescale Semiconductor / Motorola, AN2690 Datasheet - Page 19

Manufacturer Part Number

AN2690

Description

Low Frequency EEPROM Emulation on the MC68HLC908QY4

Manufacturer

Freescale Semiconductor / Motorola

Datasheet

1.AN2690.pdf (34 pages)

InitTimer Flow

Diagram

MOTOROLA

Low Frequency EEPROM Emulation on the MC68HLC908QY4

This routine sets up a timer overflow (rate = 100 Hz (10 ms)), which is used to

pace the main loop. The bus clock is approximately 8 kHz, as the MCU is driven

from the external 32768 Hz clock. This gives an overflow of 10 ms with

prescaler = 1 and modulo value set to 80d.

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Figure 11. Initialize Timer

Set prescaler to 1 and enable

Stop Timer, Reset Timer and

Set modulo to #$0050

(counter tick = 10ms)

disable overflow

TOF interrupt

Start Timer

Clear TOF

InitTimer

RTS

Appendix A: Sample Application

AN2690