m21262 Mindspeed Technologies, m21262 Datasheet - Page 17

• Manufacturer Part Number: m21262
• Description: Cdr/reclocker With 4 1 Input Multiplexer
• Manufacturer: Mindspeed Technologies

1.1.11
The M21262 supports JTAG external boundary scan, which includes all of the high-speed I/O, as well as the
traditional digital I/O.
Table 1-10.
1.1.12
Each of the four input channels contains an input equalizer to compensate for high-frequency loss. In the hardwired
mode, there is the option to set input equalization on or off. In the two-wire serial interface control mode, the default
state allows for configurable input equalization settings using Ineq_ctrl_N [2:0], for which the default setting of 100b
is optimized for trace lengths between 10–46 inches.
The input equalization settings have been optimized for a variety of backplane PCB applications, such as board
traces and cables. For board traces on FR4, the input equalizer can drive trace lengths of up to 72” at 1.6 Gbps and
up to 60” at 3.1875 Gbps. The equalizer has similar high performance on Nelco-13, Arlon 25, Rogers 3003, 4003C,
4340, GeTek PCB materials, and twinaxial
deterministic jitter accumulation effects of typical backplane interconnects, which have bandwidths of hundreds of
MHz to a few GHz. The equalizers are not expected to make a significant difference in performance with signal
data rates less than 1 Gbps.
Another component of input deterministic jitter is inter-symbol interference (ISI) due to DC offsets. By default, a DC
servo-like circuit is enabled to correct for this type of deterministic jitter, and can be disabled by setting
Ineq_ctrl [4] = 0b. The DC servo can also be used to track changes in the common mode, for single-ended
operation. When the CDR, DC servo, and AIE are all enabled, the jitter tolerance should be greater than 1 UI.
21262-DSH-001-C
MF10
MF11
MF8
MF9
Pin
Multifunction Pins for JTAG
JTAG
Input Deterministic Jitter Attenuators
Table 1-10
Function
TMS
TDO
TCK
TDI
shows the multifunction pins signal mapping for JTAG testing.
Mindspeed Proprietary and Confidential
Mindspeed Technologies
cables.
Test select
Test data input
Test clock
Test data output
The input equalizer was designed to compensate for the
®
Description
Functional Description
9