3850 datasheet(59/261 Pages) RENESAS

59 / 261 page

1-44

3850/3851 Group User’s Manual

HARDWARE

Fig. 51 State transitions of system clock

CM4 : Port Xc switch bit

0 : I/O port function (stop oscillating)

1 : XCIN-XCOUT oscillating function

CM5 : Main clock (XIN- XOUT) stop bit

0 : Oscillating

1 : Stopped

CM7, CM6: Main clock division ratio selection bit

b7 b6

0 :

φ = f(XIN)/2 ( High-speed mode)

1 :

φ = f(XIN)/8 (Middle-speed mode)

0 :

φ = f(XCIN)/2 (Low-speed mode)

1 : Not available

Notes

Reset

“0”

←→

“1”

←→

“0”

“1”

←→

“0”

“1”

←→

“0”

CM6

“1”

←→“0”

CM6

“1”

←→“0”

CPU mode register

“0”

←→

“1”

←→

“0”

(CPUM : address 003B 16)

CM7=0

CM6=1

CM5=0(8 MHz oscillating)

CM4=0(32 kHz stopped)

Middle-speed mode

(f(

φ)=1 MHz)

CM7=0

CM6=1

CM5=0(8 MHz oscillating)

CM4=1(32 kHz oscillating)

Middle-speed mode

(f(

φ)=1 MHz)

CM7=0

CM6=0

CM5=0(8 MHz oscillating)

CM4=0(32 kHz stopped)

High-speed mode

(f(

φ)=4 MHz)

CM7=1

CM6=0

CM5=0(8 MHz oscillating)

CM4=1(32 kHz oscillating)

Low-speed mode

(f(

φ)=16 kHz)

CM7=1

CM6=0

CM5=1(8 MHz stopped)

CM4=1(32 kHz oscillating)

Low-speed mode

(f(

φ)=16 kHz)

CM7=0

CM6=0

CM5=0(8 MHz oscillating)

CM4=1(32 kHz oscillating)

High-speed mode

(f(

φ)=4 MHz)

1 : Switch the mode by the allows shown between the mode blocks. (Do not switch between the modes directly without an allow.)

2 : The all modes can be switched to the stop mode or the wait mode and return to the source mode when the stop mode or the wait mode is

ended.

3 : Timer operates in the wait mode.

4 : When the stop mode is ended, a delay of approximately 1 ms occurs by connecting prescaler 12 in middle/high-speed mode.

5 : When the stop mode is ended, a delay of approximately 16 ms occurs by Timer 1 and Timer 2 in low-speed mode.

6 : Wait until oscillation stabilizes after oscillating the main clock X IN before the switching from the low-speed mode to middle/high-speed

mode.

7 : The example assumes that 8 MHz is being applied to the X IN pin and 32 kHz to the X CIN pin.

φ indicates the internal clock.

FUNCTIONAL DESCRIPTION

3850 Datasheet(PDF) 59 Page - Renesas Technology Corp

3850 Datasheet(HTML) 59 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 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL