cx28380 Mindspeed Technologies, cx28380 Datasheet - Page 57

• Manufacturer Part Number: cx28380
• Description: Cn8380 Quad T1/e1 Line Interface
• Manufacturer: Mindspeed Technologies

13, 23, 33, 43—LIU Control (LIU_CTL)
AISCLK
AUTO_AIS
TAIS
LLOOP
RLOOP
29380-DSH-001-B
AISCLK
7
length and type. Custom shape programming for alternative cable types or pulse templates can
be set using the SHAPE1–SHAPE4 registers [addr n8 – nF].
Enable Automatic ACKI Switching
switched to reference TACKI (T1) or EACKI (E1) instead of TCLK when transmitting AIS (all 1s)
data. Set AISCLK only if the system supplies an alternate line rate clock on the TACKI or EACKI
pins. Also see description of AUTO_AIS/TAIS below.
Automatic Transmit Alarm Indication Signal
Manual Transmit Alarm Indication Signal
(AUTO_AIS), the AIS generator replaces all data output on XTIP/XRING with an unframed all-
1s signal (AIS). This includes replacing data supplied from TPOSI/TNEGI and from the receiver
during Remote Line Loopback. Automatic mode sends AIS for the duration of transmit loss of
clock [TLOC; addr n5]. If AISCLK is enabled, the transmit clock is switched to use TACKI or
EACKI to transmit AIS.
Local Digital Loopback. This allows Local Digital Loopback to be active simultaneously with
the transmission of AIS. If TAIS is activated when RLOOP is enabled, AIS is transmitted using
the jitter-attenuated received clock if JAT is enabled. See the descriptions of RLOOP and
LLOOP below.
settings and input conditions.
Local Analog Loopback—Bipolar data from XTIP/XRING is internally connected to RTIP/RRING
inputs. Externally applied data on RTIP/RRING inputs is ignored. XTIP/XRING output data is
unaffected. Asserting both LLOOP and RLOOP activates Local Digital Loopback. See the
RLOOP description below.
Remote Line Loopback—Dual-rail bipolar data from the receiver (or receive JAT) is internally
connected to the transmitter (or transmit JAT). The recovered clock from the RPLL (or JCLK) is
also looped to provide the transmit clock. Loopback data retains BPV transparency. Received
data is allowed to pass to the RZCS decoder, and digital outputs are unaffected.
encoder (or transmit jitter attenuator) is internally connected to the RZCS decoder (or receive
jitter attenuator) inputs. The transmit clock, TCLK (or JCLK), is also looped to provide the
receive clock, RCKO. Externally applied data on RTIP/RRING inputs are blocked; however,
AUTO_AIS
0 = TACKI/EACKI is not used to transmit AIS
1 = TACKI/EACKI is used to transmit AIS
AIS transmission does not affect transmit data that is looped back to the receiver during
Asserting both LLOOP and RLOOP activates LDL. Dual-rail bipolar data from the TZCS
6
PULSE
000
001
010
011
100
101
110
111
Preliminary Information / Mindspeed Proprietary and Confidential
Table 2-2
0–133 ft.
133–266 ft.
266–399 ft.
399–533 ft.
533–655 ft.
ITU–T G.703
ITU–T G.703
I.431 ISDN
TAIS
5
Cable Length
Mindspeed Technologies
lists transmitter operating modes resulting from various configuration
LLOOP
4
100 Ω Twisted Pair
100 Ω Twisted Pair
100 Ω Twisted Pair
100 Ω Twisted Pair
100 Ω Twisted Pair
75 Ω Coaxial Cable
120 Ω Twisted Pair
100 Ω Twisted Pair
—
If AISCLK is active, the transmitter clock is automatically
Cable Type
—
When activated manually (TAIS) or automatically
RLOOP
3
®
T1 DSX
T1 DSX
T1 DSX
T1 DSX
T1 DSX
E1
E1
T1 CSU/NCTE
TAIS_PE
2
Application
LLOOP_PE
1
Registers
RLOOP_PE
0
R/W
49