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LH79524/LH79525 User's Guide
BITS
12
11:10
9
8
7
6
MULTIHASHEN
5
4
3
2
1
0
Table 6-9. NETCONFIG Fields (Cont'd)
NAME
Retry Test Must be programmed to 0 for normal operation. If programmed to 1, the
delay between collisions will always be one slot time. Setting this bit to 1 helps testing
the 'Too Many Entries' condition. Also used in the Pause Frame tests to reduce the
RETRY
Pause Counter's decrement time from 512 bit times, to every ETHERRXCLK cycle.
1 = Delay one slot time upon collision
0 = Normal operation
Divisor Program according to HCLK speed. This determines the HCLK divisor to gen-
erate ETHERMDC. For conformance with the IEEE 802.3 specification, MDC must not
exceed 2.5 MHz (ETHERMDC is only active during MDIO read and write operations).
DIV
00 = Divide HCLK by 8 (for HCLK up to 20 MHz)
01 = Divide HCLK by 16 (for HCLK up to 40 MHz)
10 = Divide HCLK by 32 (for HCLK up to 80 MHz)
11 = Invalid
///
Reserved Reading returns 0. Write the reset value.
Receive 1,536 Byte Frames Specifies if receive frames up to 1,536 bytes in
length are allowed instead of rejecting any frame longer 1,518 bytes.
RECBYTE
1 = Allow receive frames with up to 1,536 bytes
0 = Reject frames longer than 1,518 bytes
Unicast Hash Enable Configures EMAC to receive unicast frames when the six-bit
hash function of the destination address points to a bit that is set in the hash register.
UNIHASHEN
1 = Receive unicast frames when hash function active
0 = Normal operation
Multicast Hash Enable Configures EMAC to receive multicast frames when the six-
bit hash function of the destination address points to a bit that is set in the hash register.
1 = Receive multicast frames when hash function active
0 = Normal operation
No Broadcast Allows configuration of the EMAC so that frames addressed to a
Broadcast address of all 1s will not be received.
NOBCAST
1 = Do not receive frames sent to Broadcast address of all 1s
0 = Normal operation
Copy All Frames Allows all valid frames to be received.
CPYFRM
1 = Allow reception of all valid frames
0 = Normal operation
Jumbo Frames Enable acceptance of jumbo frames.
Note: When using jumbo frames, discard the last 4 bytes for transfers of 2047
JUMBOFRM
bytes or less, and discard the last 64 bytes for frames larger than 2047 bytes.
1 = Accept jumbo frames of up to 10,240 bytes
0 = Normal operation
Bit Rate Allows the interface to be configured for serial operation. Must be pro-
grammed before receive and transmit enable in the NETCTL register. If 1, a serial
interface is configured with transmit data being driven on pin ETHERTX[0] and re-
ceived on pin ETHERRX[0] serially. Also the ETHERCRS and ETHERRXDV pins
BITRATE
are logically ORed together so either may be used as the data valid signal.
1 = Set EMAC to serial operation
0 = Normal operation
Full Duplex Configures the transmit block to ignore the state of collisions and car-
rier sense, and allows receive while transmitting.
FULLDUPLEX
1 = Transmitter ignores the state of collision and carrier sense and
allows receive while transmitting
0 = Normal operation
///
Reserved
FUNCTION
Reading returns 0. Write the reset value.
Version 1.0
Ethernet MAC Controller
6-23
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