CP2201 datasheet(83/108 Pages) SILABS

83 / 108 page

CP2200/1

Rev. 1.0

Indirect Register 2. MACCF: MAC Configuration Register (Continued)

Bit 3:

PHEADER: Proprietary Header Select Bit

0: No proprietary header exists on the front of IEEE 802.3 frames.

1: Four bytes of proprietary header information exist on the front of IEEE 802.3 frames. These bytes

will be ignored by the CRC function.

Bit 2:

Reserved. Read = 0b; Must write 0b.

Bit 1:

LENCHK: Frame Length Checking Enable Bit

0: Frame length checking is disabled.

1: Transmit and receive frame lengths are compared to the Length/Type field. If the Length/Type

field represents a length then the check is performed. Mismatches are reported in the Transmit/

Receive status vectors.

Bit 0:

FLLDPLX: Full-Duplex Mode Enable Bit

0: MAC operates in half-duplex mode.

1: MAC operates in full-duplex mode.

Table 21. Pad Operation

PADMD1[7] PADMD0[6] PADEN[5] CRCEN[4]

Action

No padding added on transmitted packets,

check CRC

No padding added on transmitted packets,

append CRC

Pad short frames to 60 bytes, append CRC

Pad short frames to 64 bytes, append CRC

Auto Detect Tagged VLAN Frames

(IEEE802.1q)

If untagged: Pad to 60 bytes, append CRC

If tagged: Pad to 64 bytes, append CRC

CP2201 Datasheet(PDF) 83 Page - Silicon Laboratories