M38039G8HKP datasheet(64/92 Pages) RENESAS

64 / 92 page

Rev.1.10

Nov 14, 2005

Page 64 of 91

REJ03B0166-0110

3803 Group (Spec.H QzROM version)

PRELIMINARY

Notice: This is not a final specification.

Some parametric limits are subject to change.

CLOCK GENERATING CIRCUIT

The 3803 group (Spec.H QzROM version) has two built-in

oscillation circuits: main clock XIN-XOUT oscillation circuit and

sub clock XCIN-XCOUT oscillation circuit. 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

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

resistor exists on-chip.(An external feed-back resistor may be

needed depending on conditions.) However, an external feed-

back resistor is needed between XCIN and XCOUT.

Immediately after power on, only the XIN oscillation circuit

starts oscillating, and XCIN and XCOUT pins function as I/O ports.

• Frequency Control

(1) Middle-speed mode

The internal clock

φ is the frequency of XIN divided by 8. After

reset is released, this mode is selected.

(2) High-speed mode

The internal clock

φ is half the frequency of XIN.

(3) Low-speed mode

The internal clock

φ is half the frequency of XCIN.

(4) Low power dissipation mode

The low power consumption operation can be realized by

stopping the main clock XIN in low-speed mode. To stop the

main clock, set bit 5 of the CPU mode register to “1”. When the

main clock XIN is restarted (by setting the main clock stop bit to

“0”), set sufficient time for oscillation to stabilize.

The sub-clock XCIN-XCOUT oscillating circuit can not directly

input clocks that are generated externally. Accordingly, make

sure to cause an external resonator to oscillate.

Oscillation Control

(1) Stop mode

If the STP instruction is executed, the internal clock

φ stops at an

“H” level, and XIN and XCIN oscillators stop. When the

oscillation stabilizing time set after STP instruction released bit

(bit 0 of address 001016) is “0”, the prescaler 12 is set to “FF16”

and timer 1 is set to “0116”. When the oscillation stabilizing time

set after STP instruction released bit is “1”, set the sufficient time

for oscillation of used oscillator to stabilize since nothing is set to

the prescaler 12 and timer 1.

After STP instruction is released, the input of the prescaler 12 is

connected to count source which had set at executing the STP

instruction, and the output of the prescaler 12 is connected to

timer 1. Oscillator restarts when an external interrupt is received,

but the internal clock

φ is not supplied to the CPU (remains at

“H”) until timer 1 underflows. The internal clock

φ is supplied

for the first time, when timer 1 underflows. This ensures time for

the clock oscillation using the ceramic resonators to be

stabilized. When the oscillator is restarted by reset, apply “L”

level to the RESET pin until the oscillation is stable since a wait

time will not be generated.

(2) Wait mode

If the WIT instruction is executed, the internal clock

φ stops at an

“H” level, but the oscillator does not stop. The internal clock

restarts at reset or when an interrupt is received. Since the

oscillator does not stop, normal operation can be started

immediately after the clock is restarted.

To ensure that the interrupts will be received to release the STP

or WIT state, their interrupt enable bits must be set to “1” before

executing of the STP or WIT instruction.

When releasing the STP state, the prescaler 12 and timer 1 will

start counting the clock XIN divided by 16. Accordingly, set the

timer 1 interrupt enable bit to “0” before executing the STP

instruction.

<Notes>

• If you switch the mode between middle/high-speed and low-

speed, stabilize both XIN and XCIN oscillations. The sufficient

time is required for the sub clock to stabilize, especially

immediately after power on and at returning from stop mode.

When switching the mode between middle/high-speed and

low-speed, set the frequency on condition that f(XIN) >

×f(XCIN).

• When using the quartz-crystal oscillator of high frequency,

such as 16 MHz etc., it may be necessary to select a specific

oscillator with the specification demanded.

• When using the oscillation stabilizing time set after STP

instruction released bit set to “1”, evaluate time to stabilize

oscillation of the used oscillator and set the value to the timer 1

and prescaler 12.

M38039G8HKP Datasheet(PDF) 64 Page - Renesas Technology Corp

M38039G8HKP Datasheet(HTML) 64 Page - Renesas Technology Corp

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

Datasheet Descarga

Enlace URL