SCANPSC110F Datasheet, PDF (1/29 Pages) National Semiconductor (TI) – SCAN Bridge Hierarchical and Multidrop Addressable JTAG Port (IEEE1149.1 System Test Support)

October 1999
SCANPSC110F
SCAN Bridge Hierarchical and Multidrop Addressable
JTAG Port (IEEE1149.1 System Test Support)
General Description
The SCANPSC110F Bridge extends the IEEE Std. 1149.1
test bus into a multidrop test bus environment. The advan-
tage of a hierarchical approach over a single serial scan
chain is improved test throughput and the ability to remove a
board from the system and retain test access to the remain-
ing modules. Each SCANPSC110F Bridge supports up to 3
local scan rings which can be accessed individually or com-
bined serially. Addressing is accomplished by loading the in-
struction register with a value matching that of the Slot in-
puts. Backplane and inter-board testing can easily be
accomplished by parking the local TAP Controllers in one of
the stable TAP Controller states via a Park instruction. The
32-bit TCK counter enables built in self test operations to be
performed on one port while other scan chains are simulta-
neously tested.
n The 6 slot inputs support up to 59 unique addresses, a
Broadcast Address, and 4 Multi-cast Group Addresses
n 3 IEEE 1149.1-compatible configurable local scan ports
n Mode Register allows local TAPs to be bypassed,
selected for insertion into the scan chain individually, or
serially in groups of two or three
n 32-bit TCK counter
n 16-bit LFSR Signature Compactor
n Local TAPs can be tri-stated via the OE input to allow
an alternate test master to take control of the local TAPs
n The IP version of this device supports features not
described in this datasheet such as 8 slot inputs for
enhanced address capability and additional instructions.
For a completed description of the additional instructions
supported, refer to the SCANPSC110 supplemental
datasheet.
Features
n True IEEE1149.1 hierarchical and multidrop addressable
capability
Connection Diagrams
28-Pin
CDIP and Flatpak
Pin Assignment for LCC
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