STC5455 datasheet(11/56 Pages) CONNOR-WINFIELD

11 / 56 page

Page 11 of 56 TM121

Rev:P1.3

Date: October 24, 2011

STC5455

Synchronous Clock for SETS

Data sheet

Preliminary

Input and Output Frequencies

Input Frequencies

Auto-Detect Acceptable Input Frequencies

The STC5455 can automatically detect the frequency of the reference input when the user enable the auto-

detect function at the register Ref Index Selector and Ref Acceptable Freq for REF1~REF5 individually. The

acceptable frequency for auto detection is shown in Table 4.

Manually Acceptable Input Frequencies

When the frequency auto-detect function is disabled, STC5455 provides another option which allows the user

to select the manually acceptable reference frequency for REF1~REF5 individually, at the integer multiple of

8kHz (Nx8kHz, N is integer from 1 to 32767). Hence the manually acceptable reference frequency range is

8kHz to 262.136MHz, in 8kHz steps. When a manually acceptable reference frequency is used, the user need

to access the register Ref Acceptable Freq to set the integer N for associated reference input selected at the

Input Frequency = N x 8kHz, where N = 1~32767

Table 4: Auto-Detect Acceptable Ref Input Frequencies

Reference Input

Frequency

REF1 ~ REF5

8 kHz

64 kHz

19.44 MHz

38.88 MHz

77.76 MHz

1.544 MHz

2.048 MHz

6.48 MHz

8.192 MHz

16.384 MHz

25 MHz

50 MHz

125 MHz

EX_SYNC 1

EX_SYNC 2

EX_SYNC 3

2kHz or 8kHz external frame sync inputs

STC5455 Datasheet(PDF) 11 Page - Connor-Winfield Corporation