SP505 Datasheet, PDF (33/35 Pages) Sipex Corporation – WAN Multi-Mode Serial Transceiver

LOOPBACK MODE...
The SP505 is equipped with two loopback
modes. Single-ended loopback internally
connects V.28 driver outputs to V.28 receiver
inputs. The signal path is non-inverting and will
support data rates up to 120kbps. The propaga-
tion delay times are as specified in the electrical
specifications. To initiate a single-ended
loopback, the code "1010" should be written to
the driver decoder. Differential loopback is
implemented by applying "1011" to the driver
decoder. This internally connects V.11 driver
outputs to V.11 receiver inputs. The signal path
again is non-inverting; the differential loopback
data rate can be at least 5Mbps.
Under loopback conditions the receiver decoder
is disabled. While the SP505 is in either single-
ended or differential loopback mode, the driver
outputs are tri-stated and the receiver inputs are
disabled.
RD(a) 70
RxD 1
RT(a) 37
RxC 20
CS(a) 66
CTS 80
DM(a) 68
DSR 78
RR(a) 35
DCD 19
MODE: Single-Ended Loopback
DRIVER/RECEIVER
DEC₃ DEC₂ DEC₁ DEC₀
1
0
1
0
14 TxD
61 SD(a)
2 SDEN
13 DTR
58 TR(a)
3 TREN
16 RTS
54 RS(a)
4 RSEN
17 RL
47 RL(a)
18 RLEN
24 LL
51 LL(a)
IC(a) 39
RI 21
5 LLEN
22 ST
42 ST(a)
SCT(a) 76
SCT 79
SCTEN 7
RECEIVERS DRIVERS
23 STEN
15 TxC
63 TT(a)
6 TTEN
RD(a) 70
RxD 1
RD(b) 71
RT(a) 37
RxC 20
RT(b) 38
CS(a) 66
CTS 80
CS(b) 67
DM(a) 68
DSR 78
DM(b) 69
RR(a) 35
DCD 19
RR(b) 36
IC(a) 39
RI 21
IC(b) 40
SCT(a) 76
SCT 79
SCTEN 7
SCT(b) 77
MODE: Differential Loopback
DRIVER/RECEIVER
DEC₃ DEC₂ DEC₁ DEC₀
1
0
1
1
RECEIVERS DRIVERS
14 TxD
61 SD(a)
59 SD(b)
2 SDEN
13 DTR
58 TR(a)
56 TR(b)
3 TREN
16 RTS
54 RS(a)
52 RS(b)
4 RSEN
17 RL
47 RL(a)
45 RL(b)
18 RLEN
24 LL
51 LL(a)
49 LL(b)
5 LLEN
22 ST
42 ST(a)
44 ST(b)
23 STEN
15 TxC
63 TT(a)
65 TT(b)
6 TTEN
Mode
Loopback
DEC=1010
DEC=1011
Driver Output
Receiver Input
non-inverting inverting non-inverting inverting
Driver Receiver
Input Output
tri-state tri-state >10K to GND >10K to GND active
active
tri-state tri-state >10K to GND >10K to GND active
active
Power down
V_CC=V_DD=V_SS=0V
Tri-state
DEC=0000
tri-state
tri-state
clamped
tri-state >10K to GND >10K to GND inactive at ±0.6V
tri-state >10K to GND >10K to GND inactive tri-state
Rev: A Date: 1/27/04
SP505 Multi–Mode Serial Transceiver
33
© Copyright 2004 Sipex Corporation