H8SLASH3003 datasheet(163/715 Pages) RENESAS

No. de pieza	H8/3003

Descripción Electrónicos	microcontroller (MCU)

PDF	715 Pages

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Fabricante Electrónico	RENESAS [Renesas Technology Corp]

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Interval Timer: When PSRAME = 0 and DRAME = 0, the refresh controller operates as an

interval timer. After setting RTCOR, select an input clock in RTMCSR and set the CMIE bit to 1.

CMI interrupts will be requested at compare match intervals determined by RTCOR and bits

CKS2 to CKS0 in RTMCSR.

When setting RTCOR, RTMCSR, and RFSHCR, make sure that PSRAME = 0 and DRAME = 0.

Writing is disabled when either of these bits is set to 1.

7.3.2 DRAM Refresh Control

Refresh Request Interval and Refresh Cycle Execution: The refresh request interval is

determined by the settings of RTCOR and bits CKS2 to CKS0 in RTMCSR. Figure 7-2 illustrates

the refresh request interval.

Figure 7-2 Refresh Request Interval (RCYCE = 1)

Refresh requests are generated at regular intervals as shown in figure 7-2, but the refresh cycle is

not actually executed until the refresh controller gets the bus right.

Table 7-4 summarizes the relationship among area 3 settings, DRAM read/write cycles, and

refresh cycles.

RTCOR

H'00

RTCNT

Refresh request

145

H8/3003 Datasheet(PDF) 163 Page - Renesas Technology Corp