AN2074 Freescale Semiconductor / Motorola, AN2074 Datasheet - Page 7

• Manufacturer Part Number: AN2074
• Description: DSP56300 JTAG Examples
• Manufacturer: Freescale Semiconductor / Motorola

1.4 Bypass Register
1.5 ID Register
1.6 Boundary-Scan Register
The Bypass Register provides a single-bit scan path between
when a device other than the DSP56300 core-based device becomes the device under test. When the
Bypass Register is selected by the current instruction, the shift register stage is set to a logic 0 on the rising
edge of
is selected is always 0.
The 32-bit ID Register stores values that identify the device manufacturer, part number, and version and is
selected by the IDCODE instruction. It can be used to distinguish specific IEEE 1149.1-compliant parts in
a daisy-chained system. The least significant bit (bit 0) is always set to logic 1, as required by the standard;
this bit is an identity packing bit that indicates valid data. Table 2 summarizes the ID Register.
The Boundary-Scan Register in the DSP56300 devices contain bits for all signal, clock, and control pins.
All bidirectional pins have a single register bit and an associated control bit in the BSR. In the Update-DR
state, the register contains valid stimuli data. In the Capture-DR state, the Boundary-Scan Register samples
data. Data clocked into the device in the Shift-DR state can drive output pins in the subsequent Update-DR
state. At the same time, the clocking action shifts out sampled pin data from the previous Capture-DR state.
As an example of a typical Boundary-Scan Register structure, Table 3 shows the bit definitions for the
DSP56307.
Number
Bit
0
1
2
3
TCK
IRQA
IRQB
IRQC
IRQD
31–28
27–22
21–17
16–12
11–1
Pin Name
in the Capture-DR controller state. Therefore, the first bit shifted out after the Bypass Register
0
Bit Description
Table 3. DSP56307 Boundary-Scan Register Bit Definitions
Version Information
Design Center Number
Core Number
Chip Derivative Number
Manufacturer Identity
Pre-set to logic 1
Freescale Semiconductor, Inc.
Input
Input
Input
Input
For More Information On This Product,
Pin Type
Go to: www.freescale.com
DSP56300 JTAG Examples
Data
Data
Data
Data
Table 2. ID Register
Cell Type
00000001110
000110
00000
00011
0000
1
Number
Bit
72
73
74
75
TDI
Version 0
Motorola Semiconductor Israel
DSP56300
DSP56303
Motorola
Pre-set to logic 1
RESET
HAD0
HAD0
HAD1
Pin Name
and
Value
TDO
. It enhances test efficiency
Input
Input/Output
Boundary-Scan Register
Pin Type
—
—
Data
Control
Data
Control
Cell Type
7