Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Scheda Tecnica

Codici prodotto

AT91SAM9N12-EK

Programmer’s Model

ARM DDI0198D

2-35

{FCSE PID = 0}

MOV r0, #1:SHL:25

;Fetched with FCSE PID = 0

MCR p15,0,r0,c13,c0,0

;Fetched with FCSE PID = 0

;Fetched with FCSE PID = 1

Where A1, A2, and A3 are the three instructions following the fast context switch.

Context ID Register

The Context ID Register provides a mechanism to allow real-time trace tools to identify
the currently executing process in multi-tasking environments.

The contents of this register are replicated on the ETMPROCID pins of the
ARM926EJ-S processor. ETMPROCIDWR is pulsed when a write occurs to the
Context ID Register.

Table 2-27 shows the ARM instructions that you can use to access the Context ID
Register.

The format of the Context ID Register, Rd, transferred during this operation is shown
in Figure 2-16.

Figure 2-16 Context ID Register format

2.3.14

Register c14

Accessing (reading or writing) this register is reserved.

Table 2-27 Context ID register operations

Function

Data

ARM Instruction

Read context ID

Context ID

MRC p15,0,<Rd>,c13,c0, 1

Write context ID

Context ID

MCR p15,0,<Rd>,c13,c0, 1

Context identifier