RM0090: Reference manual - STMicroelectronics

Ethernet (ETH): media access control (MAC) with DMA controller RM0090
● Option to filter all error frames on reception and not forward them to the application in
Store-and-Forward mode
● Option to forward under-sized good frames
● Supports statistics by generating pulses for frames dropped or corrupted (due to
overflow) in the Receive FIFO
● Supports Store and Forward mechanism for transmission to the MAC core
● Automatic generation of PAUSE frame control or back pressure signal to the MAC core
based on Receive FIFO-fill (threshold configurable) level
● Handles automatic retransmission of Collision frames for transmission
● Discards frames on late collision, excessive collisions, excessive deferral and underrun
conditions
● Software control to flush Tx FIFO
● Calculates and inserts IPv4 header checksum and TCP, UDP, or ICMP checksum in
frames transmitted in Store-and-Forward mode
● Supports internal loopback on the MII for debugging
29.2.2 DMA features
● Supports all AHB burst types in the AHB Slave Interface
● Software can select the type of AHB burst (fixed or indefinite burst) in the AHB Master
interface.
● Option to select address-aligned bursts from AHB master port
● Optimization for packet-oriented DMA transfers with frame delimiters
● Byte-aligned addressing for data buffer support
● Dual-buffer (ring) or linked-list (chained) descriptor chaining
● Descriptor architecture, allowing large blocks of data transfer with minimum CPU
intervention;
● each descriptor can transfer up to 8 KB of data
● Comprehensive status reporting for normal operation and transfers with errors
● Individual programmable burst size for Transmit and Receive DMA Engines for optimal
host bus utilization
● Programmable interrupt options for different operational conditions
● Per-frame Transmit/Receive complete interrupt control
● Round-robin or fixed-priority arbitration between Receive and Transmit engines
● Start/Stop modes
● Current Tx/Rx Buffer pointer as status registers
● Current Tx/Rx Descriptor pointer as status registers
29.2.3 PTP features
● Received and transmitted frames time stamping
● Coarse and fine correction methods
● Trigger interrupt when system time becomes greater than target time
● Pulse per second output (product alternate function output)
901/1416 Doc ID 018909 Rev 3