LM3S613 Datasheet, PDF (152/591 Pages) List of Unclassifed Manufacturers – Microcontroller

JTAG Interface
4.5.2.2
BYPASS Data Register
The format for the 1-bit BYPASS Data Register defined by the IEEE Standard 1149.1 is shown in
Figure 4-4 on page 152. The standard requires that every JTAG-compliant device implement either
the BYPASS instruction or the IDCODE instruction as the default instruction. The LSB of the BYPASS
Data Register is defined to be a 0 to distinguish it from the IDCODE instruction, which has an LSB
of 1. This allows auto configuration test tools to determine which instruction is the default instruction.
Figure 4-4. BYPASS Register Format
0
TDI ₀ TDO
4.5.2.3
4.5.2.4
4.5.2.5
4.5.2.6
Boundary Scan Data Register
The format of the Boundary Scan Data Register is shown in Figure 4-5 on page 152. Each GPIO
pin, starting with a GPIO pin next to the JTAG port pins, is included in the Boundary Scan Data
Register. Each GPIO pin has three associated digital signals that are included in the chain. These
signals are input, output, and output enable, and are arranged in that order as can be seen in the
figure.
When the Boundary Scan Data Register is accessed with the SAMPLE/PRELOAD instruction, the
input, output, and output enable from each digital pad are sampled and then shifted out of the chain
to be verified. The sampling of these values occurs on the rising edge of TCK in the Capture DR
state of the TAP controller. While the sampled data is being shifted out of the Boundary Scan chain
in the Shift DR state of the TAP controller, new data can be preloaded into the chain for use with
the EXTEST and INTEST instructions. These instructions either force data out of the controller, with
the EXTEST instruction, or into the controller, with the INTEST instruction.
Figure 4-5. Boundary Scan Register Format
TDI
I
N
O
U
T
O
E
... I
N
O
U
T
O
E
I
N
I
N
O
U
T
O
E
... I
N
O
U
T
O TDO
E
GPIO PB6
GPIO m
RST
GPIO m+1
GPIO n
APACC Data Register
The format for the 35-bit APACC Data Register defined by ARM is described in the ARM® Debug
Interface V5 Architecture Specification.
DPACC Data Register
The format for the 35-bit DPACC Data Register defined by ARM is described in the ARM® Debug
Interface V5 Architecture Specification.
ABORT Data Register
The format for the 35-bit ABORT Data Register defined by ARM is described in the ARM® Debug
Interface V5 Architecture Specification.
152
July 14, 2014
Texas Instruments-Production Data