mcf5272 Freescale Semiconductor, Inc, mcf5272 Datasheet - Page 486

• Manufacturer Part Number: mcf5272
• Description: Mcf5272 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

Boundary Scan Register
21.4 Boundary Scan Register
The boundary scan register contains bits for all device signal and clock pins and associated
control signals. Bidirectional pins include a single scan bit for data (IO.Cell) as shown in
Figure 21-6. These bits are controlled by an enable cell, shown in Figure 21-5. The control
bit value determines whether the bidirectional pin is an input or an output. One or more
bidirectional data bits can be serially connected to a control bit as shown in Figure 21-7.
Note that when bidirectional data bits are sampled, bit data can be interpreted only after
examining the I/O control bit to determine pin direction.
Open-drain bidirectional bits require separate input and output cells as no direction control
is available from which to determine signal direction. Programmable open-drain signals
also have an enable cell (XXX.de) to select whether the pin is open drain or push-pull.
Signals with pull-up or pull-down resistors have an associated enable cell (XXX.pu); one
enable cell can control multiple resistors.
21-4
1
0
RUN-TEST/IDLE
TEST LOGIC
RESET
0
Figure 21-2. TAP Controller State Machine
1
MCF5272MCF5272 User’s Manual
0
1
1
SELECT-DR_SCAN
CAPTURE-DR
UPDATE-DR
PAUSE-DR
SHIFT-DR
EXIT1-DR
EXIT2-DR
0
1
1
0
0
0
1
1
1
0
0
0
1
1
SELECT-IR_SCAN
CAPTURE-IR
UPDATE -IR
PAUSE-IR
SHIFT-IR
EXIT1-IR
EXIT2-IR
1
0
0
0
1
1
0
1
1
0
0
MOTOROLA