CS2200-OTP

DS842F1

11

5.3

Output to Input Frequency Ratio Configuration

5.3.1

time programmable memory. Selection between the four ratios is achieved by the M[1:0] mode select

portion while the remaining 20 LSBs represent the fractional binary portion. The maximum multiplication

factor is approximately 4096 with a resolution of 0.954 PPM in this configuration. See “Calculating the

User Defined Ratio” on page 20 for more information.

The status of internal dividers, such as the internal timing reference clock divider, are automatically taken

5.3.2

Ratio Modifier (R-Mod)

register space remain unchanged). The available options for R-Mod are summarized in Table 2 on

page 11. R-Mod is enabled via the M2 pin in conjunction with the appropriate setting of the M2Config[2:0]

global parameter (see Section 5.6.2 on page 15).

Table 2. Ratio Modifier

5.3.3

To simplify operation the device handles some of the ratio calculation functions automatically (such as

when the internal timing reference clock divider is set). For this reason, the Effective Ratio does not need

to be altered to account for internal dividers.

input and output clocks as shown in the “AC Electrical Characteristics” on page 7.

Referenced Control

Parameter Definition

Ratio 0-3................................“Ratio 0 - 3” on page 18

M[1:0] ....................................“M1 and M0 Mode Pin Functionality” on page 14

RModSel[1:0]

R Modifier

00

0.5

01

0.25

10

0.125

11

0.0625

Referenced Control

Parameter Definition

Ratio 0-3................................“Ratio 0 - 3” on page 18

RModSel[1:0] ........................ “R-Mod Selection (RModSel[1:0])” section on page 17

M2Config[2:0]........................“M2 Pin Configuration (M2Config[2:0])” on page 19