MC68HC05B4 Datasheet, PDF (70/298 Pages) Motorola, Inc – High-density Complementary Metal Oxide Semiconductor (HCMOS) Microcomputer Unit

5.6
Timer during STOP mode
When the MCU enters STOP mode, the timer counter stops counting and remains at that particular
count value until STOP mode is exited by an interrupt. If STOP mode is exited by power-on or
external reset, the counter is forced to $FFFC but if it is exited by external interrupt (IRQ) then the
counter resumes from its stopped value.
Another feature of the programmable timer is that if at least one valid input capture edge occurs at
one of the TCAP pins while in STOP mode, the corresponding input capture detect circuitry is
armed.This action does not wake the MCU or set any timer flags, but when the MCU does wake-up
there will be an active input capture flag (and data) from that first valid edge which occurred during
STOP mode.
5
If STOP mode is exited by an external reset then no such input capture flag or data action takes
place even if there was a valid input capture edge (at one of the TCAP pins) during STOP mode.
5.7
Timer during WAIT mode
The timer system is not affected by WAIT mode and continues normal operation. Any valid timer
interrupt will wake-up the system.
5.8
Timer state diagrams
The relationships between the internal clock signals, the counter contents and the status of the
flag bits are shown in the following figures. It should be noted that the signals labelled ‘internal’
(processor clock, timer clocks and reset) are not available to the user.
MOTOROLA
5-12
PROGRAMMABLE TIMER
TPG
MC68HC05B6
Rev. 4