trình biên dịch mục tiêu cụ thể thiết lập tùy chọn được hiển thị trong hình tiêu cụ thể biên dịch Tùy chọn Cài đặt e) Compiler Mã Cài đặt hệ thiết lập mã thế hệ được thể hiện trong hình 2-43 Compiler Mã Cài đặt thế hệ 6. Cài đặt lắp ráp cài đặt lắp ráp được thể hiện trong hình 2-44. | Embedded Systems Development and Labs The English Edition Table 3-1 ARM Work Modes M 4 0 M 4 0 Mode Visible THUMB state registers Visible ARM state registers 1ŨŨŨŨ User LR. SR PC. CPSR . PC. CPSR 1ŨŨŨ1 FIQ . LR fiq. SP fiq PC CPSR SPSR-fiq . R14 fiq. PC CPSR SPSRJiq 10010 IRQ . LR irq. SP irq PC. irq . R14 irq PC CPSR SPSR irq 10011 Supervisor . LR SVC. SP SVC PC CPSR SPSR_svc . R14 SVC PC CPSR SPSR SVC 10111 Abort . LR abt. SP abt. PC CPSR SPSR abt . R14 abt. SPSR abt 11011 Undefined LR und. SP und PC CPSR SPSR_und . R14 Lind. PC. CPSR 11111 System . LR. SP PC. CPSR . PC. CPSR 3 Other Bits Other bits in the program status registers are reserved for future expansion. In general programmers must take care to write code in such a way that these bits are never modified. Failure to do this might result in code which has unexpected side-effects on future versions of the architecture. 3. The Assembly as Syntax and Rules Used in This Lab 1 A label is written as a symbol immediately followed by a colon The symbol then represents the current value of the active location counter. You are warned if you use the same symbol to represent two different locations the first definition overrides any other definitions. 2 Some Instructions 1 LDR The LDR Load Register instruction loads a word from the memory address calculated by addressing_mode See the ARM reference manual and writes it to register Rd . If the address is not word-aligned the loaded value is rotated right by 8 times the value of bits 1 0 Please note that the as compiler will replace the LDR instruction with a MOV of MVN instruction if that is possible. Syntax Format LDR Rd expression Where expression is a 32 bit variable that needs to be read Rd is the target register. Example LDR r1 0xff LDR r0 0xfff00000 89 Embedded Systems Development and Labs The English Edition 2 ADR ADR can read a
