SBSLITE Telecom Standard Product Data Sheet
Preliminary
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2010883, Issue 2
242
DBCTRL
The DBCTRL bit is used to pass control of the data bus drivers to the CSB pin. When the
DBCTRL bit is set to logic one and PMCTST is set to logic one, the CSB pin controls the
output enable for the data bus. While the DBCTRL bit is set, holding the CSB pin high
causes the SBSLITE to drive the data bus and holding the CSB pin low tri-states the data bus.
The DBCTRL bit overrides the HIZDATA bit. The DBCTRL bit is used to measure the drive
capability of the data bus driver pads.
PMCTST
The PMCTST bit is used to configure the SBSLITE for PMC's manufacturing tests. When
PMCTST is set to logic one, the SBSLITE microprocessor port becomes the test access port
used to run the PMC "canned" manufacturing test vectors. The PMCTST bit can be cleared
by setting CSB to logic one or by writing logic zero to the bit.
PMCATST
The PMCATST bit is used to configure the analog portion of the SBSLITE for PMC's
manufacturing tests.
12.2
JTAG Test Port
The SBSLITE JTAG Test Access Port (TAP) allows access to the TAP controller and the 4 TAP
registers: instruction, bypass, device identification and boundary scan. Using the TAP, device
input logic levels can be read, device outputs can be forced, the device can be identified and the
device scan path can be bypassed. For more details on the JTAG port, please refer to the
Operations section.
Table 25 Instruction Register (Length - 3 bits)
Instructions
Selected Register
Instruction Codes,
IR[2:0]
EXTEST
Boundary Scan
000
IDCODE
Identification
001
SAMPLE
Boundary Scan
010
BYPASS
Bypass
011
BYPASS
Bypass
100
STCTEST
Boundary Scan
101
BYPASS
Bypass
110
BYPASS
Bypass
111