Fast Ethernet Controller (FEC)
MPC885 PowerQUICC Family Reference Manual, Rev. 2
45-2
Freescale Semiconductor
— External BD tables of user-definable size allow nearly unlimited flexibility in management of
transmit and receive buffer memory
•
10/100 base-T media access control (MAC) features
— Address recognition for broadcast, single station address, promiscuous mode, and multicast
hashing
— Full MII support
— Reduced MII support
— Interrupts supported per frame or per buffer (selectable buffer interrupt functionality using the
I bit is not supported however.)
— Automatic interrupt vector generation for receive and transmit events (Tx interrupts, Rx
interrupts, and non-time critical interrupts)
— Ethernet channel uses DMA burst transactions to transfer data to and from external memory
45.1.1
FEC Block Diagram
The FEC, the embedded MPC8xx core, the system interface unit (SIU), and the CPM all use the 32-bit
internal bus.
Figure 45-1
is a block diagram of the FECs.
Figure 45-1. FEC Block Diagrams
The FEC complies with the IEEE 802.3 specification for 10- and 100-Mbps connectivity. Full-duplex
100-Mbps operation is supported at system clock rates of 40 MHz and higher. A 25-MHz system clock
supports 10-Mbps operation or half-duplex 100-Mbps operation.
The implementation of bursting DMA reduces bus usage. Independent DMA channels for accessing BDs
and transmit and receive data minimize latency and FIFO depth requirements.
Transmit and receive FIFOs further reduce bus usage by localizing all collisions to the FEC. Transmit
FIFOs maintain a full collision window of transmit frame data, eliminating the need for repeated DMA
over the system bus when collisions occur. On the receive side, a full collision window of data is received
before any receive data is transferred into system memory, allowing the FIFO to be flushed in the event of
DMAs
FIFOs
10/100
MII / RMII
Base-T
Media Access
Control
Fast
Ethernet
Controller 2
DMAs
FIFOs
10/100
MII / RMII
Base-T
Media Access
Control
Fast
Ethernet
Controller 1
Summary of Contents for PowerQUICC MPC870
Page 98: ...MPC885 PowerQUICC Family Reference Manual Rev 2 I 4 Freescale Semiconductor ...
Page 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Page 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Page 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
Page 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Page 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Page 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Page 1336: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 16 Freescale Semiconductor ...
Page 1358: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 38 Freescale Semiconductor ...
Page 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Page 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...