MPC8280 datasheet(537/1386 Pages) FREESCALE

537 / 1386 page

IEEE 1149.1 Test Access Port

MPC8280 PowerQUICC II Family Reference Manual, Rev. 1

Freescale Semiconductor

13-3

Figure 13-2. TAP Controller State Machine

13.3

Boundary Scan Register

The MPC8280’s scan chain implementation has a 878-bit boundary scan register that contains bits for all

device signal, clock pins, and associated control signals. The PORESET_B 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 MPC8280 that can be connected between TDI and TDO

when 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 13-3, Figure 13-4, Figure 13-5, and Figure 13-6 show various cell types.

Test Logic

Reset

Run—Test/Idle

Select—DR_SCAN

Capture—DR

Shift—DR

Exit1—DR

Pause—DR

Exit2—DR

Update—DR

Select—IR_SCAN

Capture—IR

Shift—IR

Exit1—IR

Pause—IR

Exit2—IR

Update—IR

MPC8280 Datasheet(PDF) 537 Page - Freescale Semiconductor, Inc