mh2040 Music Semiconductors, Inc., mh2040 Datasheet - Page 8

• Manufacturer Part Number: mh2040
• Description: Hla Packaged Asynchronous Data Recognition And Recall Processor
• Manufacturer: Music Semiconductors, Inc.

Vertical cascading is supported through a daisy chain
architecture. There are two daisy chains, one each for the
Match flag and the Full flag; the Multiple Match flag is
connected between devices through an open-drain line.
The Match flag (/MF) from a higher-priority device is
connected to the Match input (/MI) of the next
lower-priority device to provide prioritization throughout
a multiple device system. The /MF output from the
lowest-priority device provides a system Match flag. If the
delay through the daisy chain is unacceptable, the /OE
input can be used by external priority-resolution circuitry
to enable the highest-priority responder in the system.
The match conditions on the Match and Multiple Match
flag lines are persistent indicating the results of the most
recent Compare cycle. The Match flags are free to change
after the rising edge of /E during a Compare cycle, at
which time the daisy chain starts to resolve device
prioritization. Once the daisy chain has settled, the /OE
lines can be pulled LOW to access the Highest-Priority
Match address on the PA:AA bus.
HARRP - HLA Packaged Asynchronous Data Recognition-Recall Processors
8
The Multiple Match open-drain output (/MM) provides
multiple match indication when there are two or more
matches in a single device, or a device has its /MI input
LOW and has a match; the /MM flags of all devices in the
system are wire-ORed. Multiple responders can be
accessed sequentially by resetting the Highest-Priority
Match latch with the control state Advance to Next
Matching Location.
The Full flag (/FF) is cascaded from one device to the Full
Flag input (/FI) of the next lower-priority device in the
system. The /FF output from the lowest-priority device
provides a system Full flag. The Full flag is free to change
after the rising edge of /E during a Write cycle. The daisy
chains are persistent and are not conditioned by the /OE
input.
The MH2040 supports JTAG boundary-scan testing
through the pins TCK, TMS, TDI, TDO, and /TRST,
according to the IEEE 1149 Standard: Test Access Port
and Boundary-scan Architecture.
Rev. 1.0