SH7058 Datasheet, PDF (633/1130 Pages) Renesas Technology Corp – Renesas SuperHTM RISC engine

The procedure for accessing the cycle counter (CCR) and timer counter (TCNTR) using the cycle
counter double-buffer (CCR_buf) is described below.
• Read operation
Read the timer counter (TCNTR). (The value of the cycle counter (CCR) is written to the cycle
counter double-buffer (CCR_buf) simultaneously.)
Then read the cycle counter double-buffer (CCR_buf).
Peripheral data bus
Peripheral data bus
Step 1
CCR- buf
CCR- buf
Step 2
CCR
TCNT R
CCR
TCNT R
• Write operation
Write data to the cycle counter double-buffer (CCR_buf).
Then write data to the timer counter (TCNTR). (The value of the cycle counter double-buffer
(CCR_buf) is written to the cycle counter (CCR) simultaneously.)
Peripheral data bus
Peripheral data bus
Step 1
CCR- buf
Step 2
CCR- buf
CCR
TCNT R
CCR
TCNT R
Rev. 3.0, 09/04, page 592 of 1086