Fujitsu MB90895 Series Hardware Manual page 281

I Operating State of 16-bit Timer Register
The operating state of the 16-bit timer register is determined by the timer operation enable bit in the timer
control status register (TMCSR: CNTE) and the WAIT signal.The operating states include the stop state,
start trigger input wait state (WAIT state), and RUN state.
Figure 8.5-3 shows the state transition diagram for the 16-bit timer registers.
WAIT state
TIN pin : Valid for trigger input only
TOT pin : Output value of 16-bit
reload register
16-bit timer register : Hold value at stop
A time until loading, the value is undefined.
External trigger from TIN
: State transmission by hardware
: State transmission by register access
WAIT : WAIT signal (internal signal)
TRG
: Software trigger bit (TMCSR)
CNTE
: Timer operating enable bit (TMCSR)
UF
: Under flow generating flag bit (TMCSR)
RELD
: Reload select bit (TMCSR)
Figure 8.5-3 State Transition Diagram
STOP state
Reset
TIN pin : Input disabled
TOT pin : General purpose I/O port
16-bit timer register : Hold the value at stop
CNTE=0
CNTE=1
TRG=0
CNTE = 1, WAIT = 1
UF=1 &
RELD=0
(one-shot mode)
TRG=1
(software trigger) LOAD
Load the contents of 16-bit reload
register to 16-bit timer register
CNTE = 0, WAIT = 1
Immediatelp after a reset,
the value is undefined.
CNTE=1
TRG=1
RUN state
TIN pin : Function as input pin of
TOT pin : Function as output pin of
16-bit timer register : Operation
UF=1 &
RELD=1
(reload mode)
CNTE = 1, WAIT = 0
CHAPTER 8 16-bit reload timer
CNTE=0
CNTE = 1, WAIT = 0
16-bit reload timer
16-bit reload timer
TRG=1
(software trigger)
Finish loading
263