AM79C940 datasheet(73/144 Pages) AMD

tên linh kiện	AM79C940

Giải thích chi tiết về linh kiện	Media Access Controller for Ethernet (MACE??

PDF	144 Pages

Scroll/Zoom	100%

nhà sản xuất	AMD [Advanced Micro Devices]

Trang chủ	http://www.amd.com

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73 / 144 page

does not disturb the physical

medium and will prohibit frame

reception from the network. One

Internal loopback function in-

cludes the MENDEC in the loop.

Bit 0

FD_TEST

Full Duplex Test. When set, will

allow

the

MACE

device

transmit back to back packets

with 9.6

µs IPG regardless of

receive activities. The setting of

this

bit

should

also

conjunction with the setting of

Bit 0 of the Transmit Frame Con-

trol (XMTFC) (REG ADDR 2).

The setting of Bit 0 of the

XMTFC register will cause dis-

abling of transmit FCS.

To activate Full Duplex Test mode, program the MACE

device into external loopback mode (EXLOOP=1,

INLOOP=0) and set FD_TEST=1. The code sequence

would be as follows:

write 2 08 ;register XMTFC, transmit FCS disable

write 29 0b ;register UTR, receive FCS enable external

loop enable, full duplex enable

Reserved Test Register 1 (RTR1)

(REG ADDR 30)

Reserved for AMD internal use only.

Reserved Test Register 2 (RTR2)

(REG ADDR 31)

Reserved for AMD internal use only.

AM79C940 bảng dữ liệu(PDF) 73 Page - Advanced Micro Devices