COP688CL datasheet(13/40 Pages) NSC

13 / 40 page

Reset (Continued)

TLDD9766 – 7

RC l 5 c Power Supply Rise Time

FIGURE 4 Recommended Reset Circuit

Oscillator Circuits

The chip can be driven by a clock input on the CKI input pin

which can be between DC and 10 MHz The CKO output

clock is on pin G7 (crystal configuration) The CKI input fre-

quency is divided down by 10 to produce the instruction

cycle clock (1tc)

Figure 5 shows the Crystal and RC diagrams

CRYSTAL OSCILLATOR

CKI and CKO can be connected to make a closed loop

crystal (or resonator) controlled oscillator

Table A shows the component values required for various

standard crystal values

RC OSCILLATOR

By selecting CKI as a single pin oscillator input a single pin

RC oscillator circuit can be connected to it CKO is avail-

able as a general purpose input andor HALT restart pin

Table B shows the variation in the oscillator frequencies as

functions of the component (R and C) values

TLDD9766 – 9

TLDD9766 – 8

FIGURE 5 Crystal and RC Oscillator Diagrams

TABLE A Crystal Oscillator Configuration TA e 25 C

CKI Freq

Conditions

(kX)(MX)

(pF)

(MHz)

30 – 36

VCC e 5V

30 – 36

VCC e 50V

200

100 – 150

0455

VCC e 5V

TABLE B RC Oscillator Configuration TA e 25 C

CKI Freq

Instr Cycle

Conditions

(kX)

(pF)

(MHz)

(ms)

22 to 27

37 to 46

VCC e 5V

100

11 to 13

74 to 90

VCC e 5V

100

09 to 11

88 to 108

VCC e 5V

Note

3k s R s 200k 50 pF s C s 200 pF

Control Registers

CNTRL Register (Address X 00EE)

The Timer1 (T1) and MICROWIREPLUS control register

contains the following bits

SL1

SL0 Select the MICROWIREPLUS clock divide

by (00 e 2 01 e 4 1x e 8)

IEDG

External interrupt edge polarity select

(0 e Rising edge 1 e Falling edge)

MSEL

Selects G5 and G4 as MICROWIREPLUS

signals SK and SO respectively

http

www nationalcom

COP688CL Datenblatt(PDF) 13 Page - National Semiconductor (TI)

COP688CL Datenblatt(HTML) 13 Page - National Semiconductor (TI)

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

Datenblatt Download

Link URL