Timer Interface B (TIMB)

Functional Description
MC68HC908MR16/MC68HC908MR32 — Rev. 4.0 Advance Information

MOTOROLA Timer Interface B (TIMB) 227

Figure 12-1. TIMB Block Diagram

The two TIMB channels are programmable independently as input

capture or output compare channels.

NOTE: The TIMB module is not available in the 56-pin SDIP.

12.4.1 TIMB Counter Prescaler

The TIMB clock source can be one of the seven prescaler outputs or the

TIMB clock pin, PTE4/ATD12. The prescaler generates seven clock

rates from the internal bus clock. The prescaler select bits, PS[2:0], in

the TIMB status and control register select the TIMB clock source.

PRESCALER PRESCALER SELECT
TCLK
INTERNAL
16-BIT COMPARATOR
PS2 PS1 PS0
16-BIT COMPARATOR
16-BIT LATCH
TCH0H:TCH0L
MS0A
ELS0B ELS0A
PTE1
TOF
TOIE
INTER-
CHANNEL 0
TMODH:TMODL
TRST
TSTOP
TOV0
CH0IE
CH0F
CH0MAX
MS0B
16-BIT COUNTER
BUS CLOCK
PTE0/TCLKB
PTE1/TCH0B
PTE2/TCH1B
LOGIC
RUPT
LOGIC
INTER-
RUPT
LOGIC
16-BIT COMPARATOR
16-BIT LATCH
TCH1H:TCH1L
MS1A
ELS1B ELS1A
PTE2
CHANNEL 1 TOV1
CH1IE
CH1F
CH1MAX LOGIC
INTER-
RUPT
LOGIC