SH7713 datasheet(471/904 Pages) RENESAS

471 / 904 page

Section 12 Bus State Controller (BSC)

Rev.1.50 Aug. 30, 2006 Page 431 of 860

REJ09B0288-0150

Self-refresh timing is shown in figure 12.26. Settings must be made so that self-refresh

clearing and data retention are performed correctly, and auto-refreshing is performed at the

correct intervals. When self-refreshing is activated from the state in which auto-refreshing is

set, or when exiting standby mode other than through a power-on reset, auto-refreshing is

restarted if the RFSH bit is set to 1 and the RMODE bit is cleared to 0 when self-refresh mode

is cleared. If the transition from clearing of self-refresh mode to the start of auto-refreshing

takes time, this time should be taken into consideration when setting the initial value of

RTCNT. Making the RTCNT value 1 less than the RTCOR value will enable refreshing to be

started immediately.

After self-refreshing has been set, the self-refresh state continues even if the chip standby state

is entered using the LSI standby function, and is maintained even after recovery from standby

mode by an interrupt.

The self-refresh state is not cleared by a manual reset.

In case of a power-on reset, the bus state controller’s registers are initialized, and therefore the

self-refresh state is cleared.

SH7713 Datasheet(PDF) 471 Page - Renesas Technology Corp