topic Re: DSC 64-bit library difference with old library in Digital Signal Controllers

DSC 64-bit library difference with old library

daweiyou — Mon, 14 Aug 2017 09:11:44 GMT

Hi:

There are SLLD library for 64-bit operation, but there is no detailed docuemnts specified which difference between SLLD library and old library? besides 64bit operation, how about original 32bit operation? Are the all API are compatible and totally same for 32 bit? any API changed? thanks

1. runtime 56800E smm.lib

2.runtime 56800E smm_SLLD.lib

runtime 56800E_SLLD

Re: DSC 64-bit library difference with old library

xiangjun_rong — Mon, 21 Aug 2017 08:31:24 GMT

Hi, Dawei,

Pls refer to the the section 4.1.3 64-Bit Data Types in MCU_DSC_Compiler.pdf located at:

C:\FreescaleC\CW MCU v10.6\MCU\Help\PDF, if you use CodeWarrior for mcu ver10.x

I copy it here:

4.1.3 64-Bit Data Types
The compiler supports 64-bit long and double data types, although 32-bit long and double
data types are the default. To activate and use the 64-bit data types, you must:
1. Use #pragma slld on in a common header file, or in the C/C++ Preprocessor panel.

2. Use precompiled Main Standard Library (MSL) and runtime support libraries with
the _SLLD suffix (for example, use MSL C 56800E smm_SLLD.lib instead of MSL
C 56800E smm.lib and runtime 56800E smm_SLLD.lib instead of runtime 56800E
smm.lib).
3. Add * (ll_engine.text) to the code section in the linker command file.

Obviously, the _SLLD library also support 32-bit data type.

Hope it can help you

Xiangjun Rong

Re: DSC 64-bit library difference with old library

daweiyou — Tue, 22 Aug 2017 08:08:19 GMT

Hi Xiangjun:

does the library influence 32bit operation, besides 64bit operation?

Re: DSC 64-bit library difference with old library

xiangjun_rong — Tue, 22 Aug 2017 09:09:23 GMT

Hi,dawei,

It does not influence the 32 bits operation.

BTW, as you know that the the roadmap of DSP56800 core is:

DSP56800->DSP56800E->DSP56800EX

The DSP56800EX supports hardware 64 bits operation. For the DSP56800/DSP56800E, the core only supports to 16bits*16 bits to get 32 bits or 16 bits result. The DSP56800EX core supports 32bits*32bits to get 64 bits or 32 bits result.

I attach the the Family manual of DSP56800EX, especially, pls refer to section A.3 32 x 32 to 32/64 Multiply and MAC Instructions

Hope it can help you.

Xiangjun rong

Re: DSC 64-bit library difference with old library

daweiyou — Sat, 26 Aug 2017 02:04:18 GMT

Thanks, Xiangjun