CCS C Software and Maintenance Offers
FAQFAQ   FAQForum Help   FAQOfficial CCS Support   SearchSearch  RegisterRegister 

ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

CCS does not monitor this forum on a regular basis.

Please do not post bug reports on this forum. Send them to support@ccsinfo.com

driver for SPI FRAM CY15B104Q
Goto page Previous  1, 2, 3
 
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion
View previous topic :: View next topic  
Author Message
micro_debugger



Joined: 08 Oct 2009
Posts: 73

View user's profile Send private message

PostPosted: Sun Nov 03, 2019 1:26 pm     Reply with quote

Byte is 500 ns, not bit, sorry my mistake, but with gap of 1us between each byte, and sending of 7 bytes per each write, we get the 10us write time per one byte of data. We have 7x500 ns for data + 6x 1000 ns for gaps = 10 us per each byte written to the FRAM.
The 15 MHz is the limitation of the dsPIC I'm using, can not be faster.

Check also the other functions, to see if they are faster.
Ttelmah



Joined: 11 Mar 2010
Posts: 19195

View user's profile Send private message

PostPosted: Mon Nov 04, 2019 1:47 am     Reply with quote

You will find spi_read and spi_write are significantly faster.
I think I'll actually have a word with CCS about this. Basically spi_xfer
always has a wrapper round it to support the multi-byte transfers. Really
this should be removed by the optimiser when single byte operations
are used.
micro_debugger



Joined: 08 Oct 2009
Posts: 73

View user's profile Send private message

PostPosted: Mon Nov 04, 2019 3:04 am     Reply with quote

I'm already at single byte write at 4.9 us, read of single byte 4.1 us, and block of 21 bytes read 19us, so it is acceptable with my project requirements.
More will write you later on and release the final library to community.
However it is still expensive pleasure to use such FRAM as it cost about 25 EURO per IC, so only on dedicated application can be used.
Ttelmah



Joined: 11 Mar 2010
Posts: 19195

View user's profile Send private message

PostPosted: Mon Nov 04, 2019 7:13 am     Reply with quote

It's a high capacity device, so expensive.
They drop quite a lot once you buy in reasonable quantity though, so
with a bit of searching around you ought to be able to do quite a bit
better.
Display posts from previous:   
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion All times are GMT - 6 Hours
Goto page Previous  1, 2, 3
Page 3 of 3

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group