3 address inputs/loopbacks – Cirrus Logic CS61880 User Manual
Page 14
CS61880
14
DS450PP3
3.3 Address Inputs/Loopbacks
SYMBOL
LQFP
FBGA
TYPE
DESCRIPTION
A4
12
F4
I
Address Selector Input
Parallel Host Mode - During non-multiplexed parallel host
mode operation, this pin function as the address 4 input for
the parallel interface.
Hardware Mode - The A4 pin must be tied low at all times.
A3
A2
A1
A0
13
14
15
16
F3
F2
F1
G3
I
I
I
I
Non-Intrusive Monitoring/Address Selector Inputs
Parallel Host Mode - During non-multiplexed parallel host
mode operation, these pins function as address A[3:0] in-
puts for the parallel interface.
Hardware Mode - The A[3:0] pins are used for port selec-
tion during non-intrusive monitoring. In non-intrusive
monitoring mode, receiver 0’s input is internally connected
to the transmit or receive ports on one of the other 7 chan-
nels. The recovered clock and data from the selected port
are output on RPOS0/RNEG0 and RCLK0. Additionally, the
data from the selected port can be output on
TTIP0/TRING0 by activating the remote loopback function
for channel 0 (Refer to
(See Section 14.12 on page 36).
LOOP0/D0
LOOP1/D1
LOOP2/D2
LOOP3/D3
LOOP4/D4
LOOP5/D5
LOOP6/D6
LOOP7/D7
21
22
23
24
25
26
27
28
G2
H3
H2
J4
J3
J2
J1
K1
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
Loopback Mode Selector/Parallel Data Input/Output
Parallel Host Mode - In non-multiplexed microprocessor in-
terface mode, these pins function as the bi-directional 8-bit
data port. When operating in multiplexed microprocessor in-
terface mode, these pins function as the address and data
inputs/outputs.
Hardware Mode
- No Loopback - The CS61880 is in a normal operating
state when LOOP is left open (unconnected) or tied to
VCCIO/2.
- Local Loopback - When LOOP is tied High, data transmit-
ted on TTIP and TRING is looped back into the analog
input of the corresponding channel’s receiver and output on
RPOS and RNEG. Input Data present on RTIP and RRING
is ignored.
- Remote Loopback - When LOOP is tied Low the recov-
ered clock and data received on RTIP and RRING is looped
back for transmission on TTIP and TRING. Data on TPOS
and TNEG is ignored.