SNAU299 January   2024 LMX1214

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5.   5
  6. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  7. 2Hardware
    1. 2.1  Evaluation Setup Requirement
    2. 2.2  Connection Diagram
    3. 2.3  Power Requirements
    4. 2.4  How to Enable Full SPI Control
    5. 2.5  Reference Clock
    6. 2.6  Output Connections
    7. 2.7  Switch Information
    8. 2.8  Default Configuration
    9. 2.9  Divider Mode Example
    10. 2.10 Hybrid Mode: SPI and Pin Mode
  8. 3Software
    1. 3.1 Software Installation
    2. 3.2 Software Description
    3. 3.3 USB2ANY Interface
  9. 4Implementation Results
    1. 4.1 Evaluation Setup
      1. 4.1.1 Buffer and Divider Mode
  10. 5Hardware Design Files
    1. 5.1 Schematic
    2. 5.2 PCB Layout
      1. 5.2.1 PCB Layer Stack-Up
    3. 5.3 Bill of Materials
  11. 6Additional Information
    1. 6.1 Troubleshooting Guide
      1. 6.1.1 General Guidance
      2. 6.1.2 If Output Is Not Seen on CLKOUT
      3. 6.1.3 If Device Features Are Not Active
      4. 6.1.4 If Divider Frequency Is Not Accurate
    2. 6.2 Trademarks

2.2 Connection Diagram

GUID-20231220-SS0I-ZN82-JHMJ-NLRWTNH8QTQJ-low.svg

The on board TCA9555 IO expander allows the user to change pin states without manually needing to flip the position of the switches. This allows users to toggle pin modes via the GUI as well.

Table 2-1 SPI Test Points
Test Point Net
TP1 SDO
TP5 SCK
TP6 SDI
TP9 SCL
TP8 SDA
TP4 CSB
Table 2-2 I2C Test Points for IO Expander
Test Point Net
TP8 SDA
TP9 SCL
Table 2-3 Supply Voltage Test Points
Test Point Net
TP2 VCCIN
TP3 GND
TP7 VCC01
TP10 VCC23
TP11 VCLK
TP12 VAUX
TP13 VPINM
Table 2-4 VCC Power Jumpers
Header Net Short Position Configuration
J28 Use LDO or VCCIN bypassing LDO 1-2 Bypass LDO and use VCCIN directly
2-3 (EVM Default) Use on-board LDO
J29 VCC_BYP or VCC_LDO 1-2 Bypass LDO
2-3 (EVM default) Use on-board LDO
Table 2-5 Switches
Switch Net Switch Position Configuration Result

S2

CLK0_EN

 High Pulled High to VPINM via 10kOhm pull up CLK0 Enabled - can be disabled via SPI

Low

Shorted to GND via 10kOhm pull down

CLK0 Disabled & cannot be enabled via SPI

S3

 CLK1_EN

High

 Pulled High to VPINM via 10kOhm pull up CLK1 Enabled - can be disabled via SPI

Low

 Shorted to GND via 10kOhm pull down CLK1 Disabled & cannot be enabled via SPI

S4

CLK23_EN

High

 Pulled High to VPINM via 10kOhm pull up CLK2 & CLK3 Enabled - can be disabled via SPI

Low

 Shorted to GND via 10kOhm pull down CLK2 & CLK3 Disabled & cannot be enabled via SPI

S5

DIVSEL0

High

 Pulled High to VPINM via 10kOhm pull up

Set to 1

Low

 Shorted to GND via 10kOhm pull down

Set to 0

S6

DIVSEL1

 High Pulled High to VPINM via 10kOhm pull up

Set to 1

Low

 Shorted to GND via 10kOhm pull down

Set to 0

S7

MUXSEL

High

 Pulled High to VPINM via 10kOhm pull up

Sets device to divider mode

Low

 Shorted to GND via 10kOhm pull down

Sets device to buffer mode
Table 2-6 Pin Mode Strapping
Mode Switch Position DIVSELx Position Divider Value
Buffer Mode

MUXSEL[1] = Low

MUXSEL[0] = Low

N/A

N/A

Divider Mode

MUXSEL[1] = High

MUXSEL[0] = Low

DIVSEL[1] = Low

DIVSEL[0] = Low

SPI control

DIVSEL[1] = Low

DIVSEL[0] = High

Div by 2

DIVSEL[1] = High

DIVSEL[0] = Low

Div by 3

DIVSEL[1] = High

DIVSEL[0] = High

Div by 4
Note: Only divider values of 2/3/4 are available in pin mode. Divider values of 5 , 6 , 7 & 8 are valid divider values only when in SPI mode.