HD6417144 RENESAS [Renesas Technology Corp], HD6417144 Datasheet - Page 434

• Manufacturer Part Number: HD6417144
• Description: 32-Bit RISC Microcomputer SuperHTM RISC engine Family/SH7144 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

12. Watchdog Timer
Reading from TCNT, TCSR, and RSTCSR: TCNT, TCSR, and RSTCSR are read like other
registers. Use byte transfer instructions. The read addresses are H'FFFF8610 for TCSR,
H'FFFF8611 for TCNT, and H'FFFF8613 for RSTCSR.
12.6.2
If a timer counter increment clock pulse is generated during the T3 state of a write cycle to TCNT,
the write takes priority and the timer counter is not incremented. Figure 12.8 shows this operation.
Rev.4.00 Mar. 27, 2008 Page 390 of 882
REJ09B0108-0400
TCNT Write and Increment Contention
• Writing 0 to the WOVF bit
• Writing to the RSTE and RSTS bits
Address: H'FFFF8612
Address: H'FFFF8612
Figure 12.8 Contention between TCNT Write and Increment
Address
Internal write
signal
TCNT input
clock
TCNT
φ
Figure 12.7 Writing to RSTCSR
15
15
TCNT write cycle
T 1
H'A5
H'5A
TCNT address
N
T 2
8
8
Counter write data
7
7
T 3
M
Write data
H’00
0
0