Philips Semiconductors

Product specification

SCC2692

Dual asynchronous receiver/transmitter (DUART)

1998 Sep 04

21

NOTES:

1.

INTRN or OP3-OP7 when used as interrupt outputs.

2.

The test for open-drain outputs is intended to guarantee switching of the output transistor. Measurement of this response is referenced from the midpoint of the switching

test environment are pronounced and can greatly affect the resultant measurement.

VM

VOL +0.5V

VOL

WRN

OUTPUT

tIR

VM

VOL +0.5V

VOL

RDN

OUTPUT

tIR

SD00136

Figure 6. Interrupt Timing

X1/CLK

CTCLK

RxC

TxC

tCLK

tCTC

tRx

tTx

tCLK

tCTC

tRx

tTx

+5V

1K

X1

X2

X1

X2

3.6864MHz

3pF

4pF

50 TO

150 K

Ω

TO INTERNAL CLOCK DRIVERS

SCC2698B

NOTE:

C1 AND C2 SHOULD BE BASED ON MANUFACTURER’S SPECIFICATION. PARASITIC CAPACITANCE SHOULD

BE INCLUDED WITH C1 AND C2. R1 IS ONLY REQUIRED IF U1 WILL NOT DRIVE TO X1 INPUT LEVELS

TYPICAL CRYSTAL SPECIFICATION

FREQUENCY:

2 – 4MHZ

12 – 32pF

TYPE OF OPERATION:

PARALLEL RESONANT, FUNDAMENTAL MODE

NC

R1

U1

SD00137

RESISTOR REQUIRED

WHEN U1 IS A TTL DEVICE

Figure 7. Clock Timing