COP884CG datasheet(9/42 Pages) NSC

9 / 42 page

Reset (Continued)

TLDD9765 – 10

RC l 5 c Power Supply Rise Time

FIGURE 5 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 6 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 input

Table B shows the variation in the oscillator frequencies as

functions of the component (R and C) values

TLDD9765 – 11

TLDD9765 – 12

FIGURE 6 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

T1C0

Timer T1 StartStop control in timer

modes 1 and 2

Timer T1 Underflow Interrupt Pending Flag in

timer mode 3

T1C1

Timer T1 mode control bit

T1C2

Timer T1 mode control bit

T1C3

Timer T1 mode control bit

T1C3 T1C2 T1C1 T1C0 MSEL IEDG

SL1

SL0

Bit 7

Bit 0

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