scn2681t NXP Semiconductors, scn2681t Datasheet - Page 9

• Manufacturer Part Number: scn2681t
• Description: Dual Asynchronous Receiver/transmitter Duart
• Manufacturer: NXP Semiconductors

1. For bus operations, CEN and RDN (also CEN and WRN) are ANDed internally. As a consequence, the signal asserted last initiates the cycle
Philips Semiconductors
NOTE:
2004 Mar 22
Dual asynchronous receiver/transmitter (DUART)
and the signal negated first terminates the cycle.
SYMBOL
SYMBOL
t
t
t
t
PS
PH
PD
IR
NOTES:
1.
2.
SYMBOL
SYMBOL
INTRN or OP3-OP7 when used as interrupt outputs.
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
test environment are pronounced and can greatly affect the resultant measurement.
M
, to a point 0.5V above V
INTRN (or OP3–OP7 when used as interrupts) negated from:
Read RHR (RxRDY/FFULL interrupt)
Write THR (TxRDY interrupt)
Reset command (delta break interrupt)
Stop C/T command (counter interrupt)
Read IPCR (input port change interrupt)
Write IMR (clear of interrupt mask bit)
OP0–OP7
IP0–IP6
WRN
RDN
Port input setup time before RDN LOW
Port input hold time after RDN HIGH
Port output valid after WRN HIGH
t
PS
OL
INTERRUPT
. This point represents noise margin that assures true switching has occurred. Beyond this level, the effects of external circuitry and
OUTPUT
WRN
1
OLD DATA
PARAMETER
PARAMETER
PARAMETER
PARAMETER
Figure 6. Interrupt Timing
Figure 5. Port Timing
(a) INPUT PINS
(b) OUTPUT PINS
1
1
9
V
t
PD
M
t
t
PH
IR
V
NEW DATA
OL
+0.5V
V
Min
OL
0
0
–
LIMITS
Min
SD00101
–
–
–
–
–
–
LIMITS
Max
200
–
–
SCN2681T
Max
200
200
200
200
200
200
SD00102
Product data
UNIT
UNIT
UNIT
UNIT
ns
ns
ns
ns
ns
ns
ns
ns
ns