ARM Cortex M4F FPU registers to debug

Hi Akash,

MSP432 was initially designed as quiet open platform except of BSL and advanced libraries. So, I was expecting to see such registers as well. But, of course, there are some more advanced technologies and technics like DSP and FPU that could be protected from the stranger's eyes.
I understand that.

With respect,
Alexey

Akash Patel said:

Why are you trying to look at the values of the register?

I was expecting to try to use them as backup registers to speed-up computation on CPU, which is not normal, of course. ARM Cortex cannot do short cycle direct interfacing with external peripherals like RAM and Flash, but with registers can. So, that's why.

Regards,

Alexey

Thank you, Chester for your help. It was my last issue for now. OMG, these registers are double precision.

Perhaps you can instruct the IDE to show the FPU regs as double values in the register view. However, remember that the M4 FPU does not support any double precision instructions.

Alexey Bagaev said:

OMG, these registers are double precision.

The Cortex-M4 FPU provides an extension register file containing 32 single-precision registers. These can be viewed as:

• Sixteen 64-bit doubleword registers, D0-D15.
• Thirty-two 32-bit single-word registers, S0-S31.
• A combination of registers from the above views.

While the Cortex-M4 FPU only provides hardware floating point operation for single-precision, the double-precision registers can be used to pass arguments to functions which perform double-precision calculations using software.

Hmm, it was just an expression, but you can see how over people hook up to this by web search engines. Every word here is tagged outside.