TNETX3150 Datasheet, PDF (76/113 Pages) Texas Instruments – ThunderSWITCHE 15-PORT 10-/100-MBIT/S ETHERNETE SWITCH

TNETX3150/TNETX3150A
ThunderSWITCH^™ 15-PORT 10-/100-MBIT/S ETHERNET^™ SWITCH
SPWS027F – FEBRUARY 1997 – REVISED SEPTEMBER 1997
internal frame-wrap test mode
Frame-wrap mode allows the user to send a frame into a designated source port and selectively route the frame
successively to and from ports involved in the test (or return the frame directly) before retransmitting the frame
on the designated source port. By varying the number of ports between which the frame is forwarded, the
potential fault-capture area can be expanded or constrained. Initially, it is desirable to send data to and from
each port in turn, allowing the MAC-to-FIFO interface and MAC terminals to be tested for each port.
The TNETX3150/TNETX3150A provides an internal-loopback test mode. Internal loopback allows the frame
data path to be tested, and is useful for individual die burn-in testing and system testing with minimal reliance
on external parts. Internal loopback is selected by suitably setting the INTWRAP field of the DIATST register
(see DIATST register at 0x00DD). Port 00 (uplink), port 02, or port 14 can be selected as the source port for
injecting frames into the TNETX3150/TNETX3150A when internal wrap is selected. All other ports are set to
internally wrap frames (see Figure 32).
09
10
11
12
13
08
14
07
TNETX3150/
00
TNETX3150A
06
05
04
03
02
01
Figure 32. Internal Frame-Wrap Test (wrapped between multiple ports
using broadcast frames and VLAN registers)
By injecting broadcast or multicast frames into the source port and suitably setting the VLAN registers, frames
can be forwarded between internally wrapped ports before transmission of the frame on the source port.
The operational status of the PHY (or external connections to the TNETX3150/TNETX3150A) do not have to
be considered or assumed good when in internal-loopback mode.
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