Ethernet Register Descriptions; Mac Register Description - ST STM32F205 series Reference Manual

Ethernet (ETH): media access control (MAC) with DMA controller
Note: Reading the PMT control and status register automatically clears the Wakeup Frame
Received and Magic Packet Received PMT interrupt flags. However, since the registers for
these flags are in the CLK_RX domain, there may be a significant delay before this update
is visible by the firmware. The delay is especially long when the RX clock is slow (in 10 Mbit
mode) and when the AHB bus is high-frequency.
Since interrupt requests from the PMT to the CPU are based on the same registers in the
CLK_RX domain, the CPU may spuriously call the interrupt routine a second time even after
reading PMT_CSR. Thus, it may be necessary that the firmware polls the Wakeup Frame
Received and Magic Packet Received bits and exits the interrupt service routine only when
they are found to be at '0'.
28.8

Ethernet register descriptions

The peripheral registers can be accessed by bytes (8-bit), half-words (16-bit) or words (32-
bits).
28.8.1

MAC register description

Ethernet MAC configuration register (ETH_MACCR)
Address offset: 0x0000
Reset value: 0x0000 8000
The MAC configuration register is the operation mode register of the MAC. It establishes
receive and transmit operating modes.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
Reserved
rw
Bits 31:26 Reserved, must be kept at reset value.
CSTF: CRC stripping for Type frames
Bit 25
0x0600) will be stripped and dropped before forwarding the frame to the application.
Bit 24Reserved, must be kept at reset value.
Bit 23 WD: Watchdog disable
Bit 22 JD: Jabber disable
Bits 21:20 Reserved, must be kept at reset value.
908/1378
IFG
rw rw
When set, the last 4 bytes (FCS) of all frames of Ether type (type field greater than
When this bit is set, the MAC disables the watchdog timer on the receiver, and can receive
frames of up to 16 384 bytes.
When this bit is reset, the MAC allows no more than 2 048 bytes of the frame being received
and cuts off any bytes received after that.
When this bit is set, the MAC disables the jabber timer on the transmitter, and can transfer
frames of up to 16 384 bytes.
When this bit is reset, the MAC cuts off the transmitter if the application sends out more than
2 048 bytes of data during transmission.
rw rw rw rw rw rw rw rw
RM0033 Rev 8
9 8 7 6 5 4 3
rw rw rw rw rw
RM0033
2 1 0