sc26c94 NXP Semiconductors, sc26c94 Datasheet - Page 27

• Manufacturer Part Number: sc26c94
• Description: Quad Universal Asynchronous Receiver/transmitter Quart
• Manufacturer: NXP Semiconductors

Philips Semiconductors
1995 May 1
Quad universal asynchronous receiver/transmitter (QUART)
NOTE: I/O PIN DATA IS NOT LATCHED
I/O as Output
NOTES:
1. INCLUDES I/O WHEN USED AS TxRDY or RxDY/FFULL OUTPUTS AS WELL AS IRQN.
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 SIGNAL, V
SURES TRUE SWITCHING HAS OCCURRED. BEYOND THIS LEVEL, THE EFFECTS OF EXTERNAL CIRCUITRY AND TEST ENVIRONMENT ARE PRONOUNCED
AND CAN GREATLY AFFECT THE RESULTANT MEASUREMENT.
I/O as Input
WRN
RDN
CEN
I/O PINS MUST BE STABLE FOR NON-CHANGING BUS DATA DURING THE READ.
INTERRUPT
INTERRUPT
OUTPUT
OUTPUT
WRN
RDN
RESET
1
1
t
PS
OLD DATA
V
M
t
Figure 9. Interrupt Timing
Figure 8. I/O Port Timing
PD
Figure 7. Reset Timing
M
, TO A POINT 0.5V ABOVE V
t
IR
t
IR
t
27
RES
OL
. THIS POINT REPRESENTS NOISE MARGIN THAT AS-
t
PD
V
t
PH
OL
V
OL
+0.5V
+0.5V
V
OL
NEW DATA
V
OL
Product specification
SC26C94
SD00171
SD00169
SD00170