Si531x-EVB Si532x-EVB

6

Rev. 0.6

Figure 3. SPI Mode Serial Data Flow

This evaluation board requires two power inputs +3.3 V for the MCU and either 1.8, 2.5, or 3.3 V for the

Any-Frequency Precision Clock part. The power connector is J30. The grounds for the two supplies are tied

together on the EVB. There are eight LEDs, as described in Table 3.

The Evaluation board has a serial port connector (J17) that supports the following:

For details, see J17 (Table 5).

Though they are not needed on this Evaluation Board because the CPLD has low output leakage current, some

applications will require the use of external pullup and pulldown resistors when three level pins are being driven by

external logic drivers. This is particularly true for the pin-controlled parts: the Si5316, Si5322 and Si5323. Consult

the Si53xx-RM Any-Frequency Precision Clock Family Reference Manual for details.

5.6. MCU

The MCU is responsible for connecting the evaluation board to the PC so that PC resident software can be used to

control and monitor the Si532x. The USB connector is J3 and the debug port, by which the MCU is flashed, is J24.

The reset switch, SW1, resets the MCU, but not the CPLD. The MCU is a self-contained USB master and runs all

of the code required to control and monitor the Si532x, both in the MCU mode and in the pin-controlled modes.

U4 contains a unique serial number for each board and U3 is an EEPROM that is used to store configuration

information for the board. The board powers up in free run mode with a configuration that is outlined in "Appendix—

Powerup and Factory Default Settings" on page 23.

For the pin controlled parts (Si5316-EVB and Si5322/23-EVB), the contents of U3 configure the board on powerup

so that jumper plugs may be used.

If DSPLLsim is subsequently run, the jumper plugs should be removed before DSPLLsim downloads the

configuration to the EVB so that the jumpers do not conflict with the CPLD outputs.

For microprocessor parts, U3 configures the EVB for a specific frequency plan as described in "Appendix—

Powerup and Factory Default Settings" on page 23.

LVPECL outputs will not function at 1.8 V. If the Si532x part is to be operate at 1.8 V, the output format

needs to be changed by altering either the SFOUT pins (Si5316/22/23) or the SFOUT register bits (Si5319/

25/26/27).

MCU

CPLD

Si5325, Si5326

SS_CPLD_B

SCLK

MOSI

MISO

SS_B

SCLK

SDI

SDO

DUT_PWR

+3.3 V