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Updated LOOP_SCALER value for Cortex-M33 

Signed-off-by: Mahesh Mahadevan <mahesh.mahadevan@nxp.com>
pull/9910/head
Mahesh Mahadevan 2019-03-06 15:17:23 -06:00
parent 401580f364
commit 0aa8dc2383
1 changed files with 5 additions and 3 deletions
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8
platform/mbed_wait_api_no_rtos.c
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@ -51,10 +51,12 @@ void wait_us(int us)
// Cortex-M0 and Cortex-M1 take 6 cycles per iteration - SUBS = 1, 2xNOP = 2, BCS = 3 // Cortex-M0 and Cortex-M1 take 6 cycles per iteration - SUBS = 1, 2xNOP = 2, BCS = 3
#define LOOP_SCALER 6000 #define LOOP_SCALER 6000
#elif (__CORTEX_M == 0 && defined __CM0PLUS_REV) || __CORTEX_M == 3 || __CORTEX_M == 4 || \ #elif (__CORTEX_M == 0 && defined __CM0PLUS_REV) || __CORTEX_M == 3 || __CORTEX_M == 4 || \
__CORTEX_M == 23 || __CORTEX_M == 33 __CORTEX_M == 23
// Cortex-M0+, M3, M4, M23 and M33 take 5 cycles per iteration - SUBS = 1, 2xNOP = 2, BCS = 2 // Cortex-M0+, M3, M4 and M23 take 5 cycles per iteration - SUBS = 1, 2xNOP = 2, BCS = 2
// TODO - check M33
#define LOOP_SCALER 5000 #define LOOP_SCALER 5000
#elif __CORTEX_M == 33
// Cortex-M33 can dual issue for 3 cycles per iteration (SUB,NOP) = 1, (NOP,BCS) = 2
#define LOOP_SCALER 3000
#elif __CORTEX_M == 7 #elif __CORTEX_M == 7
// Cortex-M7 manages to dual-issue for 2 cycles per iteration (SUB,NOP) = 1, (NOP,BCS) = 1 // Cortex-M7 manages to dual-issue for 2 cycles per iteration (SUB,NOP) = 1, (NOP,BCS) = 1
// (The NOPs were added to stabilise this - with just the SUB and BCS, it seems that the // (The NOPs were added to stabilise this - with just the SUB and BCS, it seems that the