Digital Signal ControllersのトピックRe: Want to know a DSP/DSC support fractional arithmetic

Want to know a DSP/DSC support fractional arithmetic

397954086 — Wed, 03 Aug 2016 14:16:59 GMT

Hello, NXP.I really love your products, especially MC56F8346.I used to use MC56F8346, but its calibration arithmetic is trouble.This time come here to have a consult whether there is a DSP/DSC product support fractional arithmetic, especially can compatible with MC56F8346?

In addition, I heard that MC56F84xx have a good preformance, and support fractional arithmetic. Is there a big difference between MC56F8346 and MC56F84xx in pin relationship?Can be compatible?Which one of them is more popular?

Re: Want to know a DSP/DSC support fractional arithmetic

TICS_Fiona — Fri, 05 Aug 2016 04:14:34 GMT

Hello customer

MC56F84xxx is also fixed-point DSC. Compared with MC56F8346, MC56F84xxx supports 32-bit x 32-bit multiply and MAC operations with 32-bit and 64-bit results, bit-reverse addressing mode, new bit manipulation instruction, and improves PWM, ADC module, supports DMA, FlexMemory. For more details, please access our website:

MC56F84xxx|Digital Signal Controllers|NXP

MC56F823xx and MC56F827xx Digital Signal Controller|NXP

MC56F84xxx and MC56F82xxx are recommended for the customer, MC56F84xxx and MC56F82xxx are pin to pin compatible. But not pin to pin compatible with MC56F8346.

Best Regards

Fiona Kuang

TIC - Technical Information Center

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Re: Want to know a DSP/DSC support fractional arithmetic

397954086 — Sun, 07 Aug 2016 03:31:23 GMT

Thanks!
MC56F84xxx and MC56F82xxx are all fixed-point DSC? Isn't there something support fractional arithmetic?

Re: Want to know a DSP/DSC support fractional arithmetic

matusplachy — Mon, 03 Oct 2016 14:31:50 GMT

MC56F84xxx and MC56F82xxx are the fixed-point DSCs with fractional arithmetic support. The core has both the instructions for integer arithmetic and fractional arithmetic. The CodeWarrior 10.x Development Studio has the support of this fractional arithmetic instructions as intrinsic functions e.g. __mult for multiplication of two fractional numbers with fractional result: result = __mult(s1,s2);

More details regarding the fractional arithmetic support can be found in document : "56800/E Digital Signal Controllers: DSP56F80x/DSP56F82x Targeting Manual"

There is also available software library (RTCESL) primarily dedicated for motor control and power conversion application, but it also contains MATH library with fundamental fractional arithmetic operations, directly using the assembly instructions.