MB95630H Series
MN702-00009-1v0-E
FUJITSU SEMICONDUCTOR LIMITED
367
CHAPTER 20 16-BIT RELOAD TIMER
20.6 Operations and Setting Procedure Example
20.6.2
Event Count Mode
In this mode, the 16-bit downcounter counts down each time the valid edge is
detected on the pulses input to the TIn pin, and an interrupt request is output
to the interrupt controller when an underflow occurs ("0x0000"
→
"0xFFFF"). In
addition, a toggle waveform or square waveform can be output from the TOn
pin.
■
Event Count Mode Setup
The timer requires the register settings shown in Figure 20.6-9 to operate as an event counter.
Figure 20.6-9 Event Count Mode Setup
■
Event Count Mode
The value set in the 16-bit reload timer reload register (TMRLRHn/TMRLRLn) is reloaded to
the 16-bit counter when the count enable bit (CNTE) is set to "1" and the software trigger bit
(TRG) is set to "1". The counter counts each time the valid edge (rising, falling, or both edges
selectable) is detected on the pulses input to the TIn pin (external count clock).
●
Operation of reload mode
If the reload select bit (RELD) is "1", the value set in the 16-bit reload timer reload register
(TMRLRHn/TMRLRLn) is reloaded to the 16-bit counter and the count continues when the
16-bit counter underflows ("0x0000"
→
"0xFFFF").
The underflow interrupt request flag bit (UF) in the 16-bit reload timer control status register
(lower) (TMCSRLn) is set to "1" when an underflow occurs ("0x0000"
→
"0xFFFF") in the
16-bit counter, and an interrupt request is output if the underflow interrupt enable bit (INTE) is
set to "1".
The TOn pin can output a toggle waveform that is inverted each time an underflow occurs.
Figure 20.6-10 shows the count operation in reload mode.
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
TMCSRHn
-
-
CSL2
CSL1
CSL0
MOD2 MOD1 MOD0
1
1
1
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
TMCSRLn
-
OUTE
OUTL
RELD
INTE
UF
CNTE
TRG
1
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
TMRLRHn
D15
D14
D13
D12
D11
D10
D9
D8
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
TMRLRLn
D7
D6
D5
D4
D3
D2
D1
D0
: Used bit
1 : Set to "1"
Set initial value of counter (reload value) (upper)
Set initial value of counter (reload value) (lower)