ACS8525 Semtech Corporation, ACS8525 Datasheet - Page 8

• Manufacturer Part Number: ACS8525
• Description: Line Card Protection Switch For Sonet/sdh Systems
• Manufacturer: Semtech Corporation

Specifications” on page 98 for more information on
electrical compatibility.
Input frequencies supported range from 2 kHz to
155.52 MHz. Common E1, DS1, OC-3 and sub-divisions
are supported as spot frequencies that the DPLLs will
directly lock to. Any input frequency, up to 100 MHz, that
is a multiple of 8 kHz can also be locked to via an inbuilt
programmable divider.
Preconfiguring Inputs
Each input device has to be preconfigured with:
Table 4 Input Reference Source Selection and Priority Table
Notes: (i) TTL ports (compatible also with CMOS signals) support clock speeds up to 100 MHz, with the highest spot frequency being
Revision 3.00/October 2003 © Semtech Corp.
ADVANCED COMMUNICATIONS
SEC1 TTL
SEC2 TTL
SEC1 DIFF
SEC2 DIFF
SYNC1
SYNC2
SEC3
SYNC3
Port Name
Expected input frequency cnfg_ref_source_frequency
register (Reg. 22 to 25 and Reg. 28)
Technology (TTL or PECL/LVDS) where applicable, via
cnfg_differential_inputs (Reg. 36)
Selection Priority (Reg. 19, 1A and 1C).
(iii) SEC1 TTL and SEC2 TTL ports are on pins SEC1 and SEC2. SEC1 DIFF (Differential) port uses pins SEC1POS and SEC1NEG, similarly
(ii) PECL and LVDS ports support the spot clock frequencies listed above plus 155.52 MHz (and 311.04 MHz for Output O1 only).
77.76 MHz. The actual spot frequencies are: 2 kHz, 4 kHz, 8 kHz (and N x 8 kHz), 1.544 MHz (SONET)/2.048 MHz (SDH), 6.48 MHz,
19.44 MHz, 25.92 MHz, 38.88 MHz, 51.84 MHz, 77.76 MHz. SONET or SDH input rate is selected via Reg. 34 Bit 2, ip_sonsdhb).
SEC2DIFF uses pins SEC2POS and SEC2NEG.
0011
0100
0101
0110
0111
1000
1001
1010
Number (Bin)
Channel
TTL/CMOS
TTL/CMOS
PECL/LVDS
PECL default
PECL/LVDS
PECL default
TTL/CMOS
TTL/CMOS
TTL/CMOS
TTL/CMOS
Technology
Input Port
Up to 100 MHz (see Note (i))
Up to 100 MHz (see Note (i))
Up to 100 MHz (see Note (i))
Default (SONET): 8 kHz Default (SDH): 8 kHz
Default (SONET): 8 kHz Default (SDH): 8 kHz
Up to 155.52 MHz (see Note (ii))
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
Up to 155.52 MHz (see Note (ii))
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
2/4/8 kHz auto-sensing
2/4/8 kHz auto-sensing
Default (SONET): 19.44 MHz Default (SDH): 19.44 MHz
2/4/8 kHz auto-sensing
FINAL
Page 8
Table 4 gives details of the input reference ports, showing
the input technologies and the range of frequencies
supported on each port; the default spot frequencies and
default priorities assigned to each port on power-up or by
reset are also shown.
SDH and SONET networks use different default
frequencies; the network type is selectable using the
cnfg_input_mode Reg. 34 Bit 2, ip_sonsdhb.
On power-up or by reset, the default will be set by the state
of the SONSDHB pin (pin 64). Specific frequencies and
priorities are set by configuration.
The frequency selection is programmed via the
cnfg_ref_source_frequency register (Reg. 22 - Reg. 28).
For SONET, ip_sonsdhb = 1
For SDH, ip_sonsdhb = 0
Frequencies Supported
ACS8525 LC/P
DATASHEET
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2
3
0
0
n/a
n/a
4
n/a
Default
Priority