SH7713 datasheet(540/904 Pages) RENESAS

540 / 904 page

Section 14 Timer Unit (TMU)

Rev.1.50 Aug. 30, 2006 Page 500 of 860

REJ09B0288-0150

When a TCNT count-down results in an underflow (H'00000000

→ H'FFFFFFFF), the underflow

flag (UNF) in TCR of the relevant channel is set. The TCOR value is simultaneously set in TCNT

itself and the count-down continues from that value.

TCNT is initialized to H'FFFFFFFF by a power-on reset or manual reset, but is not initialized, and

retains its contents, in standby mode.

14.3

TMU Operation

Each of the three channels has a 32-bit TCNT and a 32-bit TCOR. TCNT counts down. The auto-

reload function enables synchronized counting and counting by external events.

14.3.1

Counter Operation

When the STR0 to STR2 bits in TSTR are set to 1, the corresponding TCNT starts counting.

When TCNT underflows, the underflow flag (UNF) of the corresponding TCR is set. At this time,

if the UNIE bit in TCR is 1, an interrupt request is sent to the CPU. Also at this time, the value is

copied from TCOR to TCNT and the down-count operation is continued.

Count Operation Setting Procedure: An example of the procedure for setting the count

operation is shown in figure 14.2.

SH7713 Datasheet(PDF) 540 Page - Renesas Technology Corp