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Arne

Beginner

Date of registration: Jul 29th 2010

Posts: 5

1

Thursday, June 13th 2013, 8:32am

embOS/IP Example for Embedded Artists Board LPC1788

Hello,

I got a question regarding the IP code in 'IP_Config_LPC1788.c'.
In:

C/C++ Source code

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void IP_X_Config(void) {
	(...)
	IP_NI_LPC17xx_ConfigAddr(0x20084000, 0x20000000);  // Set the address of the Ethernet MAC and Ethenrnet RAM.
	(...)
}

The first parameter for IP_NI_LPC17xx_ConfigAddr() is the base address of the EMAC, but the second just points to the start of AHB-RAM.
So I guess the function uses/reserves space in AHB-RAM. But how much space? So I can spare out the area in my linker script.

best regards,
Arne

SEGGER - Oliver

Super Moderator

Date of registration: Nov 14th 2007

Posts: 41

2

Thursday, June 13th 2013, 9:07am

Hello Arne,

By default the LPC17xx driver uses 4 Tx and 4 Rx buffers.

One Tx buffer set consists of an 8 byte descriptor, 4 byte status and 1536 byte buffer for the packet itself.
One Rx buffer set consists of an 8 byte descriptor, 8 byte status and 1536 byte buffer for the packet itself.

This results in a total of 12400 byte that is used from the start of the configured Ethernet RAM.

Best regards,
Oliver