Bypass Instruction; Idcode Instruction; Waferid Instruction; Table 300: Jtag Device Id Register - Broadcom BCM1250 User Manual

BCM1250/BCM1125/BCM1125H
IR Value Instruction
0x33 reserved
0x34 SCANMC
0x35 reserved
0x36 SCANSCD
0x37 reserved
0x38 SCANALL
0x39 reserved
0x3A BSRMODE
0x3B TRACECURCNT
0x3C CLAMP
0x3D SAMPLE/
PRELOAD
0x3E INTEST
0x3F BYPASS

BYPASS Instruction

The required BYPASS instruction allows the processor to remain in a functional mode and selects the Bypass
register to be connected between TDI and TDO. The BYPASS instruction allows serial data to be transferred
through the processor from TDI to TDO without affecting its operation. The bit code of this instruction is defined
to be all ones by the IEEE 1149.1 standard. All unused instructions default to the BYPASS instruction.

IDCODE Instruction

The IDCODE instruction selects the Device Identification (ID) register to be connected between TDI and TDO.
The Device ID register is a 32 bit shift register containing the 11 bit manufacture id (11'h150), the 16 bit part-
number (this matches the part number in the system_revision register) and the 4 bit version number. The
idcode register is scanned out LSB first and is shown in
3 3 2 2
1 0 9 8
Jtag
Version
Number
v v v v p p p p p p p p p p p p p p p p 0 0 1 0 1 0 1 0 0 0 0 1
The version number is 4'h1 for prototype BCM1250, 4'h2-4'h8 or 4'hb for initial production BCM1250 and 4'h9
for later production BCM1250 (stepping C0). The version number is 4'h1 for initial production BCM1125/H.

WAFERID Instruction

The WAFERID instruction selects the WaferId register to be connected between TDI and TDO. The WaferId
register is a 32 bit shift register containing a manufacturing lot code number. The register is scanned out LSB
Page 424 Section 15: JTAG and Debug
Table 299: JTAG Instructions
Broadcom Use Only. Selects MC Chain.
Broadcom Use Only. Selects SCD Scan Chain.
Broadcom Use Only. Selects All Agent Scan Chains in Series.
Keep boundary scan register active even if other JTAG commands used.
Selects the current trace event counts for scan out.
Selects the BSR onto the outputs and selects the bypass register between TDO and TDI.
Selects the boundary scan register. Cause a snapshot to be taken of the state of the pins
on the rising edge of TCLK next time the state machine is in the Capture-DR state. This
is as required by the JTAG standard.
Sets up boundary scan for intest mode. This selects all of the inputs of the chip for control
by JTAG.
Bypass Mode. Select the bypass register between TDI and TDO, as required by the JTAG
standard.

Table 300: JTAG Device ID Register

2 2 2 2 2 2 2 2
7 6 5 4 3 2 1 0
JTAG part number
B r oadco m C orp or ati on
(Cont.)
Function
Table 300.
1 1 1 1 1 1 1 1
9 8 7 6 5 4 3 2
User Manual
1 1
1 0 9 8 7 6 5 4 3 2 1 0
JTAG Manufacturer
Document 1250_1125-UM100CB-R
10/21/02
1