SCANSTA111MTX/NOPB National Semiconductor, SCANSTA111MTX/NOPB Datasheet - Page 8

• Manufacturer Part Number: SCANSTA111MTX/NOPB
• Description: IC SCAN BRIDGE MULTIDROP 48TSSOP
• Manufacturer: National Semiconductor

Specifications of SCANSTA111MTX/NOPB

• Applications: Testing Equipment
• Interface: IEEE 1149.1
• Voltage - Supply: 3 V ~ 3.6 V
• Package / Case: 48-TSSOP
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: SCANSTA111MTX

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Following a hardware reset, the TAP controller state-machine
is in the Test-Logic-Reset (TLR) state; the 'STA111-selection
state-machine is in the Wait-For-Address state; and each of
the three port-selection state-machines is in the Parked-
TLR state. The 'STA111 is then ready to receive Level-1
protocol, followed by Level-2 protocol.
Tester/SCANSTA111 Interface
An IEEE 1149.1 system tester sends instructions to a
'STA111 via that 'STA111's backplane scan-port. Following
test logic reset, the 'STA111's selection state-machine is in
the Wait-For-Address state. When the 'STA111's TAP con-
troller is sequenced to the Shift-IR state, data shifted in
through the TDI
register. Note that prior to successful selection of a 'STA111,
data is not shifted out of the instruction register and out
through the 'STA111's TDO
scan operations. Instead, as each new bit enters the instruc-
tion register's most-significant bit, data shifted out from the
least-significant bit is discarded.
When the instruction register is updated with the address da-
ta, the 'STA111's address-recognition logic compares the
B
input is shifted into the 'STA111's instruction
B
FIGURE 5. Relationship Between SCANSTA111 State Machines
output, as it is during normal
8
seven least-significant bits of the instruction register with the
7-bit assigned address which is statically present on the S
(0-6)
pared with the reserved Broadcast and Multi-cast addresses.
If an address match is detected, the 'STA111-selection state-
machine enters one of the two selected states. If the scanned
address does not match a valid single-slot address or one of
the reserved broadcast/multi-cast addresses, the 'STA111-
selection state-machine enters the Unselected state.
Note that the SLOT inputs should not be set to a value cor-
responding to a multi-cast group, or to the broadcast address.
Also note that the single 'STA111 selection process must be
performed for all 'STA111s which are subsequently to be ad-
dressed in multi-cast mode. This is required because each
such device's Multicast Group Register (MCGR) must be pro-
grammed with a multi-cast group number, and the MCGR is
not accessible to the test controller until that 'STA111 has first
entered the Selected-Single-'STA111 state.
Once a 'STA111 has been selected, Level-2 protocol is used
to issue commands and to access the chip's various registers.
inputs. Simultaneously, the scanned-in address is com-
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