SH7052 datasheet(382/919 Pages) RENESAS

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Multiplied Clock Correction Function: Channel 10’s three 16-bit correction counters

(TCNT10D, TCNT10E, TCNT10F) and correction counter clear register (TCCLR10) have a

correction function that makes the interval between edges input from TI10 the frequency

multiplication value set in TIOR10.

When AGCK is input, the value in TCNT10D multiplied by the multiplication factor set in

TIOR10 is transferred to TCNT10E. At the same time, TCNT10D is incremented.

TCNT10E counts up on AGCK1. TCNT10E loads TCNT10D on AGCK, and counts up again on

AGCK1. Using the counter correction select bit (CCS) in TIOR10, it is possible to select whether

or not TCNT10E is halted when TCNT10D = TCNT10E.

TCNT10F has the peripheral clock (P

φ) as its input and is constantly compared with TCNT10E.

When the TCNT10F value is smaller than that in TCNT10E, TCNT10F is incremented and

outputs a corrected multiplied clock signal (AGCKM).

When the TCNT10E value exceeds the TCNT10F value (when TCNT10E loads TCNT10D), no

count-up operation is performed. AGCKM is output to the channel 1 to 5 free-running counters

(TCNT1 to TCNT5).

Channel 10 also has a correction counter clear register (TCCLR10). The correction counters

(TCNT10D, TCNT10E, TCNT10F) and channel 1 and 2 free-running counters (TCNT1 and

TCNT2) can be cleared when TCNT10F reaches the value set in TCCLR10.

TCNT10D operation is shown in figure 10.32, TCNT10E operation in figure 10.33, TCNT10F

operation (at startup) in figure 10.34, TCNT10F operation (end of cycle, with correction) in figure

10.35, and TCNT10F operation (end of cycle, without correction) in figure 10.36.

Pø

TST10

AGCK

TCNT10D

Clock

Shifter output

TCNT10D

0000

Note: In case of multiplication factor of 32

0060

0040

0020

Figure 10.32 TCNT10D Operation

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