11-32
MCF5272 User’s Manual
Programming Model
11.5.24 FEC Initialization
In the FEC, the descriptor control machine initializes a few registers whenever the
ETHER_EN control is asserted. The transmit and receive FIFO pointers are reset, the
transmit backoff random number is initialized, and the transmit and receive blocks are
activated. After the FEC initialization sequence is complete, the hardware is ready for
operation, waiting for R_DES_ACTIVE and X_DES_ACTIVE to be asserted by the user.
11.5.24.1 User Initialization (after setting ETHER_EN)
The user initializes portions of the FEC after setting ETHER_EN. The exact values depend
on the particular application. The sequence probably resembles the steps shown in
Table 11-33, though these could also be done before asserting ETHER_EN.
3
Set IVEC (define ILEVEL)
4
Set R_FSTART (optional)
5
Set X_FSTART (optional)
6
Set ADDR_HIGH and ADDR_LOW
7
Set HASH_TABLE_HIGH and HASH_TABLE_LOW
8
Set R_BUFF_SIZE
9
Set R_DES_START
10
Set X_DES_START
11
Set R_CNTRL
12
Set X_CNTRL
13
Set MII_SPEED (optional)
14
Initialize (Empty) TxBD
15
Initialize (Empty) RxBD
Table 11-33. User Initialization (after ETHER_EN)
Step Description
1
Fill Receive Descriptor Ring with Empty Buffers
2
Set R_DES_ACTIVE
Table 11-32. User Initialization Process (before ETHER_EN) (Continued)
Step Description
Summary of Contents for DigitalDNA ColdFire MCF5272
Page 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Page 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Page 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Page 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Page 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Page 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Page 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Page 338: ...13 44 MCF5272 User s Manual Application Examples ...
Page 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Page 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Page 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Page 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...