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Hello to all,
I am trying to figure out the variation in current consumption as well as in clock cycles due to different memory regions and different offsets. During various experiments, I have found the following results:
LDR R4,[R1,#0x0] (R1 = 0x00000000 (Flash) with 0 offset) : Current = 2.60mAmps & Cycles = 2
LDR R4,[R1,#0x1] (R1 = 0x00000000 (Flash) with 1 offset) : Current = 2.07mAmps & Cycles = 4
LDR R4,[R1,#0x2] (R1 = 0x00000000 (Flash) with 2 offset) : Current = 2.30mAmps & Cycles = 3
LDR R4,[R1,#0x3] (R1 = 0x00000000 (Flash) with 3 offset) : Current = 2.08mAmps & Cycles = 4
from offset 4 it repeats the order. I mean Offset = 4 is equal to Offset = 0 ; Offset = 5 is equal to Offset = 1 ; Offset = 6 is equal to Offset = 2 ; Offset = 7 is equal to Offset = 3 ; Offset = 8 is equal to Offset = 0 and so on....
Similarly, while access SRAMX also :
LDR R4,[R1,#0x0] (R1 = 0x04000000 (Flash) with 0 offset) : Current = 2.88mAmps & Cycles = 1
LDR R4,[R1,#0x1] (R1 = 0x04000000 (Flash) with 1 offset) : Current = 2.30mAmps & Cycles = 3
LDR R4,[R1,#0x2] (R1 = 0x04000000 (Flash) with 2 offset) : Current = 2.65mAmps & Cycles = 2
LDR R4,[R1,#0x3] (R1 = 0x04000000 (Flash) with 3 offset) : Current = 2.29mAmps & Cycles = 3
On the basis of observation, I have three questions:
Kindly help me out with this. I am using LPCXpresso 54114 board, with ARM Cortex-M4 processor. And all the measurement have been taken at 12MHz.
Thanking you,
Regards,
Himanshu