Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK 데이터 시트
제품 코드
AT91SAM9N12-EK
Programmer’s Model
ARM DDI0198D
Copyright © 2001-2003 ARM Limited. All rights reserved.
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
A1
;Fetched with FCSE PID = 0
A2
;Fetched with FCSE PID = 0
A3
;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 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.
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.
Register.
The format of the Context ID Register, Rd, transferred during this operation is shown
in Figure 2-16.
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
31
0