mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 1119

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

IEEE 1149.1 Test Access Port
21.2 THE BOUNDARY SCAN REGISTER
The MPC823 scan chain implementation has a 397-bit boundary scan register that contains
bits for all device signal, clock pins, and associated control signals. However, the XTAL,
EXTAL, and XFC pins are associated with analog signals and are not included in the
boundary scan register. An IEEE-1149.1-compliant boundary scan register has been
included on the MPC823. This 397-bit boundary scan register can be connected between
the TDI and TDO signals when the extest or sample / preload instructions are selected. It is
used for capturing signal pin data on the input pins, forcing fixed values on the output signal
pins, and selecting the direction and drive characteristics (a logic value or high impedance)
of the bidirectional and three-state signal pins. Figure 21-3 through Figure 21-6 depict the
various cell types.
DATA FROM
SYSTEM
LOGIC
1 — EXTEST | CLAMP
0 — OTHERWISE
G1
1
1
Freescale Semiconductor, Inc.
MUX
For More Information On This Product,
Figure 21-3. Output Pin Cell (O.Pin)
FROM LAST CELL
MPC823 REFERENCE MANUAL
Go to: www.freescale.com
SHIFT DR
G1
1
1
MUX
CLOCK DR
D
C
TO NEXT CELL
UPDATE DR
D
C
TO OUTPUT
BUFFER
MOTOROLA