HD6437101 RENESAS [Renesas Technology Corp], HD6437101 Datasheet - Page 193

• Manufacturer Part Number: HD6437101
• Description: 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

Free-Running Count Operation and Periodic Count Operation: Immediately after a reset, the
MTU’s TCNT counters are all designated as free-running counters. When the relevant bit in TSTR
is set to 1 the corresponding TCNT counter starts up-count operation as a free-running counter.
When TCNT overflows (from H'FFFF to H'0000), the TCFV bit in TSR is set to 1. If the value of
the corresponding TCIEV bit in TIER is 1 at this point, the MTU requests an interrupt. After
overflow, TCNT starts counting up again from H'0000.
Figure 8.4 illustrates free-running counter operation.
Select counter clearing
Select output compare
Start count operation
Select counter clock
Operation selection
<Periodic counter>
H'FFFF
H'0000
CST bit
TCFV
Periodic counter
Set period
register
source
TCNT value
Figure 8.3 Example of Counter Operation Setting Procedure
Figure 8.4 Free-Running Counter Operation
[1]
[2]
[3]
[4]
[5]
<Free-running counter>
Free-running counter
Start count operation
Section 8 Multifunction Timer Pulse Unit (MTU)
Rev.1.00 Sep. 18, 2008 Page 159 of 522
[5]
[1] Select the counter clock
[2] For periodic counter
[3] Designate the TGR
[4] Set the periodic counter
[5] Set the CST bit in TSTR to
with bits TPSC2 to TPSC0
in TCR. At the same time,
select the input clock edge
with bits CKEG1 and
CKEG0 in TCR.
operation, select the TGR
to be used as the TCNT
clearing source with bits
CCLR2 to CCLR0 in TCR.
selected in [2] as an output
compare register by means
of TIOR.
cycle in the TGR selected
in [2].
1 to start the counter
operation.
REJ09B0069-0100
Time