Dear NXP Support,
we're trying to implement a swap routine by using the DSMC Module.
Therefore we want to use the lwdcbx asm instruction.
We're using the following code to do this (Greenhills Assembler Macro):
__asm uint32 Hal_Swap(uint32 Addr, uint32 Value)
%reg Addr %con Value
/* prepare the decoration for the SWAP instruction */
se_li r6, Value /* load value in r6 */
e_lis r5, 0x5000 /* r5 = 0x50000000 */
se_or r6, r5 /* Value = Value | r5 */
/* lwdcbx -> Load Word Decorated with Cache Bypass */
lwdcbx r3, r6, Addr /* SWAP Addr with r3 */
We expect the following behavior (as described in MPC5748GRM Rev. 4, 07/2015 - Chapter 18.104.22.168.2):
1. The "old" value of Addr is stored in r3
2. The value of r5 (WD28 in r6) is stored at Addr.
What we get is only the old value in r3, but no storage operation is performed at Addr.
We are using the following Micro:
Thanks in advance and best regards,