PIC32MX795F512LT-80I/BG [MICROCHIP]

IC MCU 32BIT 512KB FLASH 121BGA;


型号：	PIC32MX795F512LT-80I/BG
厂家：	MICROCHIP
描述：	IC MCU 32BIT 512KB FLASH 121BGA 时钟微控制器外围集成电路
文件：	总2页 (文件大小：10K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

PIC32MX6/7 family with embedded Ethernet

controller – PHY support

This document briefly explains how to add a new PHY to the MCHP TCPIP-BSD stack.

Note: The same approach applies to the MCHP TCPIP stack.

Table of Contents

Supported PHYs

How to add a new PHY

Supported PHY’s

•

The PIC32MX6-7 families with embedded Ethernet controller have support for external

MII/RMII connected PHY’s. Currently we support:

National DP83848 PHY.

SMSC LAN 8700 PHY.

Support for other PHY's will be added in the future.

How to add a new PHY

Microchip provides a PHY interface library that is being used as part of the MAC driver for the

TCPIP stack.

The basic concepts behind this PHY library are:

1. Communication to the PHY is done using MIIM interface. For access to the external PHY

registers over the MIIM interface the communication functions provided by the Ethernet

Controller Peripheral Library are used (“..path\Microchip\MPLAB

C32\pic32mx\include\peripheral\eth.h”).

2. All PHYs support a standard set of registers with well known functionality. (As part of the

IEEE 802.3 Clause 22).

3. Few functions that are vendor specific have to be added for particular PHY’s.

The functions that the current TCPIP stack MAC driver uses for communicating and configuring

the external PHY are prototyped in

“..install path\Microchip\Include\TCPIP-BSD\eth_phy.h”

and implemented in the

“..install path\Microchip\TCPIP-BSD\eth_phy\eth_phy.c”.

To add support for a new PHY you have to add the implementation for the

following

functions (the prototypes of the functions are in

“..install path\Microchip\Include\TCPIP-BSD\eth_phy.h”):

1. extern unsigned int EthPhyMIIMAddress(void):

a. does not take parameters;

b. Should return the address the PHY responds to. Depends on

the hardware design.

Note: all PHY’s respond to address 0.

c. Can be inlined/#defined

2. extern unsigned int EthPhyMIIMClock(void):

a. does not take parameters;

b. Should return the maximum clock frequency that the PHY can

use for the MIIM transactions.

i. Most PHY’s should support 2 MHz.

ii. National DP83848C supports 25 MHz, for example.

c. Can be inlined/#defined

3. extern eEthRes EthPhyConfigureMII(eEthPhyCfgFlags cFlags):

a. This function should configure the PHY in one of MII/RMII

operation modes.

b. The relevant input flags are:

i. ETH_PHY_CFG_RMII if RMII configuration is requested

ii. ETH_PHY_CFG_MII if MII configuration is requested

c. It should return:

i. ETH_RES_OK for success

ii. An error code if the requested configuration is not

supported.

4. extern eEthRes EthPhyConfigureMdix(eEthOpenFlags oFlags):

a. The function should configure the MDIX mode for the PHY.

b. The relevant input flags are:

i. ETH_OPEN_MDIX_AUTO if auto MDIX is requested

ii. else ETH_OPEN_MDIX_NORM/ETH_OPEN_MDIX_SWAP for

normal/swap mode.

c. It should return:

i. ETH_RES_OK for success

ii. An error code if the requested mode is not supported.

Additional Notes:

1. All functions in the PHY library are defined as weak. You can

replace any of the functions with your own implementation if need

arises. The function header in the “..install

path\Microchip\Include\TCPIP-BSD\eth_phy.h” explains what

input/output and behavior the respective function should have.

2. Take a look in the “..install path\Microchip

Solutions\Microchip\TCPIP-BSD\eth_phy\nat_dp83848c.c” or

“..install path\Microchip Solutions\Microchip\TCPIP-

BSD\eth_phy\smsc_8700.c” for an implementation example. Follow

the same approach.

3. All functions needed to access the PHY MIIM registers are part of

the provided Ethernet library.

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