SC28C94 Philips Semiconductors, SC28C94 Datasheet - Page 26

• Manufacturer Part Number: SC28C94
• Description: Quad universal asynchronous receiver/transmitter QUART
• Manufacturer: Philips Semiconductors

1. The minimum time indicates that read data will remain valid until the bus master drives CEN and/or RDN to High.
2. The fact that this parameter is negative means that the Dnn line may actually become valid after CEN and WRN are both Low.
3. In a Write operation, the bus master must hold the write data valid either until drives CEN and/or WRN to High, or until the QUART drives
4. Test condition for interrupt and I/O outputs: C
Philips Semiconductors
AC ELECTRICAL CHARACTERISTICS
V
NOTES:
5. Consecutive write operations to the upper four bits of the Command Register (CR) require at least three X1/CLK edges; four X1/CLK edges
6. Address is latched at leading edge of a read or write cycle.
1998 Aug 19
CC
Quad universal asynchronous receiver/transmitter (QUART)
NO
NO.
DACKN to Low, whichever comes first.
Test condition for rest of outputs: C
in the ‘X1/CLK divide by 2 edges’ according to register 2E or 2F setting.
10
1
2
3
4
5
6
7
8
9
= 5V
DACKN
X1/CLK
A[5:0]
D[7:0]
WRN
CEN
RDN
FIGURE
FIGURE
10%, T
6
6
6
6
6
6
6
6
6
6
A
= –40_C to 85_C, unless otherwise specified.
Setup: A[5:0] valid to CEN Low
Hold: A[5:0] valid after CEN Low
Access: Later of CEN Low and RDN Low, to Dnn valid (read)
Later of CEN Low and (RDN or WRN as applicable) Low, to DACKN Low
Earlier of CEN High or RDN High, to Dnn released (read)
Earlier of CEN High or (RDN or WRN as applicable) High, to DACKN released
Earlier of CEN High or (RDN or WRN as applicable) High, in one cycle, to later
of CEN Low and (RDN or WRN as applicable) Low, for the next cycle
Setup, Dnn valid (write) to later of CEN Low and WRN Low
Later of CEN Low and WRN Low, to earlier of CEN High or WRN High
Hold: Dnn valid (write) after DACKN Low, CEN High or WRN High
Normal Operation:
From Power Down:
1
2
3
Figure 6. A Read Cycle Followed by a Write Cycle with DACKN
4
L
3
= 150pF
4
L
CHARACTERISTIC
CHARACTERISTIC
4
= 50pF, forced current for V
READ CYCLE
6
5
6
5
6
26
7
7
7
7
OL
1
2
= 4.0mA; forced current for V
1
8
8
3
2
4
4
9
X1 edges
WRITE CYCLE
110/115
9
10 + 2
9
Min
–30
9
10
45
50
0
0
0
OH
5
LIMITS
= 400 A, RL = 2.7k to V
Typ
10
10
6
10
90/122 + 3
X1 edges
6
110/115
Product specification
SC28C94
Max
150
30
30
SD00677
5
UNIT
UNIT
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
CC
.