M37207M8-059SP datasheet(76/121 Pages) MITSUBISHI

76 / 121 page

MITSUBISHI MICROCOMPUTERS

M37207MF-XXXSP/FP, M37207M8-XXXSP

M37207EFSP/FP

SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER

and ON-SCREEN DISPLAY CONTROLLER

Fig. 76. Ceramic Resonator Circuit Example

Fig. 77. External Clock Input Circuit Example

(3) Low-Speed Mode

If the internal clock is generated from the sub-clock (XCIN), a low

power consumption operation can be realized by stopping only the

main clock XIN. To stop the main clock, set bit 6 (CM6) of the CPU

mode register (00FB16) to “1.” When the main clock XIN is restarted,

the program must allow enough time to for oscillation to stabilize.

Note that in low-power-consumption mode the XCIN-XCOUT drivability

can be reduced, allowing even lower power consumption (20

µA with

f (XCIN) = 32kHz). To reduce the XCIN-XCOUT drivability, clear bit 5

(CM5) of the CPU mode register (00FB16) to “0.” At reset, this bit is

set to “1” and strong drivability is selected to help the oscillation to

start. When an STP instruction is executed, set this bit to “1” by soft-

ware before executing.

CLOCK GENERATING CIRCUIT

This microcomputer has 2 built-in oscillation circuits. An oscillation

circuit can be formed by connecting a resonator between XIN and

XOUT (XCIN and XCOUT). Use the circuit constants in accordance with

the resonator manufacturer’s recommended values. No external re-

sistor is needed between XIN and XOUT since a feed-back resistor

exists on-chip. However, an external feed-back resistor is needed

between XCIN and XCOUT. When using XCIN-XCOUT as sub-clock,

clear bits 7 and 6 of the mixing control register to “0.” To supply a

clock signal externally, input it to the XIN (XCIN) pin and make the

XOUT (XCOUT) pin open. When not using XCIN clock, connect the

XCIN to VSS and make the XCOUT pin open.

After reset has completed, the internal clock

φ is half the frequency of

XIN. Immediately after poweron, both the XIN and XCIN clock start

oscillating. To set the internal clock

φ to low-speed operation mode,

set bit 7 of the CPU mode register (address 00FB16) to “1.”

Oscillation Control

(1) Stop mode

The built-in clock generating circuit is shown in Figure 78. When the

STP instruction is executed, the internal clock

φ stops at HIGH. At

the same time, timers 3 and 4 are connected by hardware and “FF16”

is set in timer 3 and “0716” is set in the timer 4. Select f(XIN)/16 or

f(XCIN)/16 as the timer 3 count source (set bit 0 of the timer mode

over, set the timer 3 and timer 4 interrupt enable bits to disabled (“0”)

before execution of the STP instruction. The oscillator restarts when

external interrupt is accepted. However, the internal clock

φ keeps its

HIGH until timer 4 overflows, allowing time for oscillation stabilization

when a ceramic resonator or a quartz-crystal oscillator is used.

(2) Wait mode

When the WIT instruction is executed, the internal clock

φ stops in

the “H” level but the oscillator continues running. This wait state is

released at reset or when an interrupt is accepted (Note). Since the

oscillator does not stop, the next instruction can be executed at once.

Note: In the wait mode, the following interrupts are invalid.

(1) VSYNC interrupt

(2) CRT interrupt

(3) f(XIN)/4096 interrupt

(4) Timer 1 and 2 interrupts using TIM2 pin input as count

source

(5) Timer 1 interrupt using f(XIN)/4096 or f(XCIN)/4096 as

count source

(6) Timer 3 interrupt using TIM3 pin input as count source

(7) Multi-master I2C-BUS interface interrupt

(8) Timer 4 interrupt using f(XIN)/2 or f(XCIN)/2 as count souce

XCIN

XIN

CCIN

Microcomputer

XCOUT

CCOUT

XOUT

CIN

COUT

XCIN

Microcomputer

External oscillation

circuit or external

pulse

XCOUT XIN

XOUT

Open

External oscillation

circuit

Vcc

Vss

Vcc

Vss

M37207M8-059SP Datasheet(PDF) 76 Page - Mitsubishi Electric Semiconductor

M37207M8-059SP Datasheet(HTML) 76 Page - Mitsubishi Electric Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL