MAC7200 datasheet(171/976 Pages) FREESCALE

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Debug Implementation

MAC7200 Microcontroller Family Reference Manual, Rev. 2

Freescale Semiconductor

8.4.1.1

TCK Routing

The TCK signal from the pad is synchronized, and then drives the TCK inputs of the PTI logic, Nexus logic

and the ARM7. See Section 8.4.2, “Synchronization” for more details on how TCKEN is used to

synchronize TMS and TDI.

Figure 8-2. JTAG TCK Routing

8.4.1.2

TMS Routing

The TMS signal from the pad is synchronized, and then drives the TMS inputs of the PTI logic, Nexus

logic and the ARM7. The TMS input of the SoC must be valid on the rising edge of the TCK clock, with

the appropriate setup and hold requirements. If the TMS signal is asserted based on the falling clock edge

of TCK, and the maximum TCK frequency is not exceeded, then the setup and hold requirements for TMS

are guaranteed to be met.

Figure 8-3. JTAG TMS Routing

8.4.1.3

TDI Routing

The TDI signal from the pad is synchronized, and then muxed in to drive the TDI inputs of the PTI logic,

Nexus logic and the ARM7. The synchronized signal is muxed in order to provide additional security when

the debug is disabled in the system for Flash security. When the debug is disabled, the INTEST instruction

is selected, and the TAP state machine is in the Shift-DR state, the TDI input to the platform is tied low.

The TDI input to the PTI logic (SC4/5/6/7) is always driven by dbg_tdi_sync, thus allowing the writing

and reading of SC4/5/6/7 even when debug is disabled. This is to allow the user to run the JTAG Lockout

TCK

ipp_ind_tck

PTI

Synch.

Logic

dbg_tcken_sync dbg_tcken_platform

To ARM7/Nexus

TMS

ipp_ind_tms

PTI

Synch.

Logic

dbg_tms_sync

dbg_tms_platform

To ARM7/Nexus

MAC7200 Datasheet(PDF) 171 Page - Freescale Semiconductor, Inc