![](http://datasheet.mmic.net.cn/100000/ID80C32E-L16SHXXX_datasheet_3493627/ID80C32E-L16SHXXX_1033.png)
1033
SAM9X35 [DATASHEET]
11055E–ATARM–10-Mar-2014
CLK: MDC Clock Divider
Set according to system clock speed. This determines by what number system clock is divided to generate MDC. For confor-
mance with 802.3, MDC must not exceed 2.5 MHz (MDC is only active during MDIO read and write operations).
RTY: Retry Test
Must be set to zero for normal operation. If set to one, the back off between collisions is always one slot time. Setting this bit to
one helps testing the too many retries condition. Also used in the pause frame tests to reduce the pause counters decrement time
from 512 bit times, to every rx_clk cycle.
PAE: Pause Enable
When set, transmission pauses when a valid pause frame is received.
RBOF: Receive Buffer Offset
Indicates the number of bytes by which the received data is offset from the start of the first receive buffer.
RLCE: Receive Length field Checking Enable
When set, frames with measured lengths shorter than their length fields are discarded. Frames containing a type ID in bytes 13
and 14 — length/type ID = 0600 — are not counted as length errors.
DRFCS: Discard Receive FCS
When set, the FCS field of received frames is not copied to memory.
EFRHD
Enable Frames to be received in half-duplex mode while transmitting.
IRXFCS: Ignore RX FCS
When set, frames with FCS/CRC errors are not rejected and no FCS error statistics are counted. For normal operation, this bit
must be set to 0.
Value
Name
Description
0MCK_8
MCK divided by 8 (MCK up to 20 MHz).
1MCK_16
MCK divided by 16 (MCK up to 40 MHz).
2MCK_32
MCK divided by 32 (MCK up to 80 MHz).
3MCK_64
MCK divided by 64 (MCK up to 160 MHz).
Value
Name
Description
0
OFFSET_0
No offset from start of receive buffer.
1
OFFSET_1
One-byte offset from start of receive buffer.
2
OFFSET_2
Two-byte offset from start of receive buffer.
3
OFFSET_3
Three-byte offset from start of receive buffer.