C674x ADD and SUB instructions issue

The issue is not solved at the following post: https://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/438821

I have reproduced the issue by a simple code with correct argument ordering. The SUB instruction does not work when the same unit is used for the instructions and when there is NOP 2 between instructions.

For example:

06B4F218            ADDSP.L1X     A7,B13,A13
00002000            NOP           2
060440D8            SUB.L1        2,A1,A12

06B4FE3A            SUBSP.S2X     B7,A13,B13
00002000            NOP           2
0604A5A2            SUB.S2        5,B1,B12

Please see the attached file for a series of assembly code: (Please visit the site to view this file)

If the instructions are successive (there is not NOP) or there is NOP except 2 cycles between the instructions, it works fine. It seems not to work only when 3 cycles passed after the ADDSP or SUBSP instruction.

In addition, the ADD instruction does not also work.

For example:

0119B21A            ADDSP.L2X     B13,A6,B2
00002000            NOP           2
0604405A            ADD.L2        2,B1,B12

0119BEB8            SUBSP.S1X     B6,A13,A2
00002000            NOP           2
0604A1A0            ADD.S1        5,A1,A12

Please see the attached file for a series of assembly code: (Please visit the site to view this file)

Furthermore, I have reproduced the issue on C6713.

Please see the attached file for a series of assembly code: (Please visit the site to view this file) (Please visit the site to view this file)

Why do the ADD and SUB instructions not work?

Best regards,

Daisuke