MAC-PHY interface using RMII not initialized (reset) on the LPC Expresso 4337 board

lpcware — Wed, 15 Jun 2016 19:18:34 GMT

Content originally posted in LPCWare by vijayendar.sridharan on Mon Jan 18 08:24:47 MST 2016
Hi All,

1. I'm using the LPC Expresso board having the 4337 NXP Microcontroller with a Cortex M3 ARM core. The PHY interface has a SMSC 8720A chip.

2. When building and running the lwIP TCP echo (standalone, no RTOS) project, downloaded from LPC Expresso website, I'm unable to initialize the SMSC 8720A chip. As a result, no data is received/can be sent from/to the MAC.

3. When I try to bring it out of reset by setting the reset bit (bit 15) of the BASIC CONTROL REGISTER (index 0), I get only 0xFF as the data read from this register.

4. Data expected: Bits 15 and 11 should be zero. There's a 250 ms timeout value for this RESET to happen, but the code times out. The USE_RMII flag is enabled in the code.

5. The Yellow and Orange LEDs blink when I insert a standard Ethernet cable (CAT5/CAT3) into the RJ45 jack, I guess this rules out power supply issues.

Any ideas/suggestions on what could be wrong? Is there any jumper/mode pin I have to change on the board? Any help is greatly appreciated.

Regards,
Vijayendar S

LPC Microcontrollers中的主题 MAC-PHY interface using RMII not initialized (reset) on the LPC Expresso 4337 board

MAC-PHY interface using RMII not initialized (reset) on the LPC Expresso 4337 board