Philips Semiconductors
Product specification
SC28L92
3.3V–5.0V Dual Universal Asynchronous
Receiver/Transmitter (DUART)
2000 Jan 21
13
ÁÁÁÁ
ÁÁÁÁ
UNIT
ÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁ
LIMITS
4
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
PARAMETER
ÁÁÁÁ
ÁÁÁÁ
SYMBOL
ÁÁÁÁ
UNIT
ÁÁÁÁ
Max
ÁÁÁ
Typ
ÁÁÁ
Min
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
PARAMETER
ÁÁÁÁ
SYMBOL
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Receiver Timing, external clock (See Figure 13)
ÁÁÁÁ
ÁÁÁÁ
t
*RXS
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
RxD data setup time to RxC high
ÁÁÁ
ÁÁÁ
50
ÁÁÁ
ÁÁÁ
40
ÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁ
ns
ÁÁÁÁ
ÁÁÁÁ
t
*RXH
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
RxD data hold time from RxC high
ÁÁÁ
ÁÁÁ
50
ÁÁÁ
ÁÁÁ
40
ÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁ
ns
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
68000 or Motorola bus timing (See Figures 6, 7, 8)
10
ÁÁÁÁ
ÁÁÁÁ
t
DCR
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
DACKN Low (read cycle) from X1 High
10
ÁÁÁ
ÁÁÁ
ÁÁÁ
ÁÁÁ
15
ÁÁÁÁ
ÁÁÁÁ
20
ÁÁÁÁ
ÁÁÁÁ
ns
ÁÁÁÁ
ÁÁÁÁ
t
DCW
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
DACKN Low (write cycle) from X1 High
ÁÁÁ
ÁÁÁ
ÁÁÁ
ÁÁÁ
15
ÁÁÁÁ
ÁÁÁÁ
20
ÁÁÁÁ
ÁÁÁÁ
ns
ÁÁÁÁ
ÁÁÁÁ
t
DAT
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
DACKN High impedance from CEN or IACKN High
ÁÁÁ
ÁÁÁ
ÁÁÁ
ÁÁÁ
8
ÁÁÁÁ
ÁÁÁÁ
10
ÁÁÁÁ
ÁÁÁÁ
ns
ÁÁÁÁ
ÁÁÁÁ
t
CSC
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
CEN or IACKN setup time to X1 High for minimum DACKN cycle
ÁÁÁ
ÁÁÁ
10
ÁÁÁ
ÁÁÁ
8
ÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁ
ns
NOTES:
1. Parameters are valid over specified temperature and voltage range.
2. All voltage measurements are referenced to ground (GND). For testing, all inputs swing between 0.4 V and 3.0 V with a transition time of
5 ns maximum. For X1/CLK this swing is between 0.4 V and 0.8*V
CC
. All time measurements are referenced at input voltages of 0.8 V and
2.0 V and output voltages of 0.8 V and 2.0 V, as appropriate.
3. Test conditions for outputs: CL = 125 pF, except open drain outputs. Test conditions for open drain outputs: C
L
= 125 pF,
constant current source = 2.6mA.
4. Typical values are the average values at +25
°
C and 5V.
5. Timing is illustrated and referenced to the WRN and RDN Inputs. Also, CEN may be the “strobing” input. CEN and RDN (also CEN and
WRN) are ORed internally. The signal asserted last initiates the cycle and the signal negated first terminates the cycle.
6. Guaranteed by characterization of sample units.
7. If CEN is used as the “strobing” input, the parameter defines the minimum High times between one CEN and the next. The RDN signal must
be negated for t
RWD
to guarantee that any status register changes are valid.
8. Minimum frequencies are not tested but are guaranteed by design.
9. Clocks for 1X mode should maintain a 60/40 duty cycle or better.
10. Minimum DACKN time is t
DCR
= t
DSC
+ t
DCR
+ two positive edges of the X1 clock. For faster bus cycles, the 80XXX bus timing may be used
while in the 68XXX mode. It is not necessary to wait for DACKN to insure the proper operation of the SC28C92. In all cases the data will be
written to the SC28L92 on the falling edge of DACKN or the rise of CEN. The fall of CEN initializes the bus cycle. The rise of CEN ends the
bus cycle. DACKN low or CEN high completes the write cycle.
0
20
40
60
80
100
120
140
160
180
200
220
240
60
55
50
45
40
35
30
25
20
15
10
5
0
V
CC
= 3.3V @ +25
°
C
5.0V @ +25
°
C
pF
T
dd
(ns)
125 pF
30 pF
230 pF
SD00684
12 pF
100 pF
NOTES:
Bus cycle times:
(80XXX mode): t
DD
+ t
RWD
= 70ns @ 5V, 40ns @ 3.3V + rise and fall time of control signals
(68XXX mode) = t
CSC
+ t
DAT
+ 1 cycle of the X1 clock @ 5V + rise and fall time of control signals
Figure 3. Port Timing vs. Capacitive Loading at typical conditions