MU9C8148
REGISTER SET DESCRIPTION
BIT
NAME
DESCRIPTION
00H: Control Register
15
14
RESET
TEXAS
If RESET is HIGH, a reset of the MU9C8148 takes place.
If TEXAS is HIGH, the MU9C8148 is programmed for the Texas Instruments TMS380CX6 MAC con-
troller.
13
12
11
10
ASSRQ
M/S
If ASSRQ is HIGH, the /RQ and /RQI mechanism become active, to permit sharing a LANCAM with
another MU9C8148. If this bit is LOW, both lines are inactive, so no arbitration takes place.
If M/S is HIGH, this MU9C8148 is a Master while sharing a LANCAM with another MU9C8148. If this bit
is ZERO, this MU9C8148 is a Slave. If bit ASSRQ is LOW, the M/S bit is “don't care”.
If TBO is HIGH, all incoming frames are filtered by the Transparent Bridging block only. No SR bridging
takes place.
If DISSTE is HIGH, all Spanning Tree Explorer frames are discarded. The MU9C8148 signals the MAC
to flush these frames. If DISSTE is LOW, STE frames are accepted per the programmed filtering criteria.
FF indicates the level of the /FI input.
TBO
DISSTE
9
FF
8
7
RDFCP
INT
If RDFCP is HIGH, access to the Error Counter 17H is reset to point to DUPL7–0 and IRI7–0.
INT indicates the inverse of the level of the /INT output.
6–0
APR6–0
APR6–0 point to the location in the IB which can be accessed through the IB Register.
01H: Frame Type Selection Register
15
14
13
12
11
10
9
MSRENBL
MSRFILT
LSRENBL
LSRFILT
1SRENBL
1SRFILT
2SRENBL
2SRFILT
MTRENBL
MTRFILT
LTRENBL
LTRFILT
1TRENBL
1TRFILT
If MSRENBL is LOW, every MAC frame containing an RIF is discarded. The MAC is signalled to flush
the frame. If MSRENBL is HIGH, the MSRFILT bit determines if the frame is filtered or copied directly.
MSRENBL is “don't care” if TBO is HIGH.
If MSRFILT is LOW, the MU9C8148 signals the MAC chip to copy every MAC frame containing an RIF. If
MSRFILT is HIGH, the MU9C8148 checks the RIF and forwards the frame if the programmed forwarding
conditions are met. MSRFILT is “don't care” if TBO is HIGH.
If LSRENBL is LOW, every LLC frame containing an RIF is discarded. The MAC is signalled to flush the
frame. If LSRENBL is HIGH, the LSRFILT bit determines if the frame is filtered or copied directly.
LSRENBL is “don't care” if TBO is HIGH.
If LSRFILT is LOW, the MU9C8148 signals the MAC to copy every LLC frame containing an RIF. If
LSRFILT is HIGH, the MU9C8148 checks the RIF and forwards the frame if the programmed forwarding
conditions are met. LSRFILT is “don't care” if TBO is HIGH.
If 1SRENBL is LOW, every reserved type 1 frame containing an RIF is discarded. The MAC is signalled
to flush the frame. If 1SRENBL is HIGH, the 1SRFILT bit determines if the frame is filtered or copied
directly. This bit is “don't care” if TBO is HIGH.
If 1SRFILT is LOW, the MU9C8148 signals the MAC chip to copy every reserved type 1 frame containing
an RIF. If 1SRFILT is HIGH, the MU9C8148 checks the RIF and forwards the frame if the programmed
forwarding conditions are met. This bit is “don't care” if TBO is HIGH.
If 2SRENBL is LOW, every reserved type 2 frame containing an RIF is discarded. The MAC is signalled
to flush the frame. If 2SRENBL is HIGH, the 2SRFILT bit determines if the frame is filtered or copied
directly. This bit is “don't care” if TBO is HIGH.
If 2SRFILT is LOW, the MU9C8148 signals the MAC to copy every reserved type 2 frame containing an
RIF. If 2SRFILT is HIGH, the MU9C8148 checks the RIF and forwards the frame if the programmed
forwarding conditions are met. This bit is “don't care” if TBO is HIGH.
If MTRENBL is LOW, every MAC frame not containing an RIF is discarded. The MAC chip is signalled to
flush the frame. If MTRENBL is HIGH, the MTRFILT bit determines if the frame is filtered or copied
directly. If TBO is HIGH, filtering is also done on MAC frames containing an RIF.
If MTRFILT is LOW, the MU9C8148 signals the MAC to copy every MAC frame not containing an RIF. If
MTRFILT is HIGH, the MU9C8148 checks the DA and forwards the frame if the forwarding conditions
are met, whether or not the frame contains an RIF.
If LTRENBL is LOW, every LLC frame not containing an RIF is discarded. The MAC chip is signalled to
flush the frame. If LTRENBL is HIGH, the LTRFILT bit determines if the frame is filtered or copied
directly. if TBO is HIGH, filtering is also done on LLC frames containing an RIF.
If LTRFILT is LOW, the MU9C8148 signals the MAC to copy every LLC frame not containing an RIF. If
LTRFILT is HIGH, the MU9C8148 checks the DA and forwards the frame if the forwarding conditions are
met, whether or not the frame contains an RIF.
If 1TRENBL is LOW, every reserved type 1 frame not containing an RIF is discarded. The MAC is
signalled to flush the frame. If 1TRENBL is HIGH, the 1TRFILT bit determines if the frame is filtered or
copied directly. If TBO is HIGH, filtering is also done on reserved type 1 frames with an RIF.
If 1TRFILT is LOW, the MU9C8148 signals the MAC to copy every reserved type 1 frame not containing
an RIF. If 1TRFILT is HIGH the MU9C8148 checks the DA and forwards the frame if the forwarding
conditions are met, whether or not the frame contains an RIF.
8
7
6
5
4
3
2
Rev. 5.5 Draft web
10
MUSIC [ MUSIC SEMICONDUCTORS ]
