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Posts: 21
Registered: ‎10-07-2015

compatible with C8051F381

Hey
I have corresponded with larger flash.
With identical Foot Print
there is?
Thanks in advance

Posts: 301
Registered: ‎09-04-2013

Re: compatible with C8051F381

@elib The Flash size is 64 kB for C8051F381.

 

Currently 64 kB Flash is the largest size that we have for 8-bit USB MCU families.

 

There are some 8-bit MCUs with 96/128 kB Flash without USB function.

 

If need larger Flash (more than 64 kB Flash) with USB function, you can refer to our 32-bit MCUs, such as Leopard Gecko, Giant Gecko, and Wonder Gecko devices.

 

http://www.silabs.com/products/mcu/32-bit/Pages/32-bit-microcontrollers.aspx

 

Posts: 21
Registered: ‎10-07-2015

Re: compatible with C8051F381

I do not have usb
But I would like Foot Print identical.
I have a PCB and I do not want to edit a new

Posts: 7,804
Registered: ‎08-13-2003

Re: compatible with C8051F381

I have corresponded with larger flash.

I guess that means that you need a larger flash

But I would like Foot Print identical

 

none such

 

this day and age, unless it as issue of large tables, I (who love the 8-bitters) consider it a mistake to use an 8 bitter for apps requiring 64k+.  what are you doing that require this?

erik
Posts: 21
Registered: ‎10-07-2015

Re: compatible with C8051F381

I need to increase table for improving the algorithm

Posts: 7,804
Registered: ‎08-13-2003

Re: compatible with C8051F381

[ Edited ]

if you would show and explain what you are actually doing, there might be help, there are means of reducing table sizes, if it was clear what you are doing one of those might fit.

 

as an example I, once, reduced a thermistor linearizing table size to 1/4 with no loss of precision

erik
Posts: 21
Registered: ‎10-07-2015

Re: compatible with C8051F381

I have three arrays of 5100 values with float type.microprocessor calculates them according to a certain equation.

Posts: 21
Registered: ‎10-07-2015

Re: compatible with C8051F381

as an example I, once, reduced a thermistor linearizing table size to 1/4 with no loss of precision

 

how?

 

Highlighted
Posts: 7,804
Registered: ‎08-13-2003

Re: compatible with C8051F381

[ Edited ]

simple example reducing to half:

original 

0:1

1:4

2:7

3:12

4:16

5:21

6:26

7:32

8:36 // added for below

 

reduced by half:

0:1

2:7

3:16

4:26

5:36

 

shift index 1 right, save "dropped bit:,

if "dropped bit = 0. result is there (table[index])

if dropped bit:= 1

result is pointed to by index + ([pointed to by index+1 - pointed to by index]/2)

 

in this coarse example you may get a small error, with more digits in values, the error disappears

 

BTW to make it work faster/better can't you use scaling instead of float? I doubt your min/max it beyond what could be accomplished with scaling. that would also give you some free memory, since the FP routines are not exactly small.

 

erik
<a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero</font></font> </a> jmg
Posts: 1,033
Registered: ‎04-27-2004

Re: compatible with C8051F381


elib wrote:

I have three arrays of 5100 values with float type.microprocessor calculates them according to a certain equation.


What is the equation, numeric limits, and what precision do you actually need ?

What is the Sensor + ADC error specs ?

How quickly do you need the results ?

 

Floating point libraries are usually around 4k bytes on the 8051, and items like Power can be used to curve-fit, with precision usually well above sensor variations.