Sign in
Search adsp
Subscribe to adsp
adsp by Keywords
AD1819 | AD7332 | ADSP-2106 | ADSP-21060 | ADSP-21065L | ADSP-2116 | ADSP-21160M | ADSP-2181 | ADSP-218x | ADSP-219 | ADSP-2199 | ADSP219 | BF531 | BF532 | BF533 | BF535 | Blackfin | FFT | JTAG | LDF | SDRAM | SHARC | SPORT | UART | VDSP++ | VisualDSP
Discussion Groups
Discussion Groups | Analog Devices DSPs | how to achieve 4Gbyte memory addressing in blackfin
Technical discussions related to Analog Devices DSPs (including Blackfin, TigerSHARC, SHARC and ADSP-21xx DSPs).
how to achieve 4Gbyte memory addressing in blackfin - Suhas Kadu - Jan 25 1:27:00 2005
|
Hi ,
in blackfin processor,
how to address 4Gbyte memory using just (1:19) ,nineteen
address line.
can anybody explain,how it is to be done ,say for
bf531.
Regards
suhas kadu
|
(You need to be a member of adsp -- send a blank email to adsp-subscribe@yahoogroups.com )
Re: how to achieve 4Gbyte memory addressing in blackfin - Mike Rosing - Jan 25 10:49:00 2005
|
On Tue, 25 Jan 2005, Suhas Kadu wrote: > Hi , > in blackfin processor, > how to address 4Gbyte memory using just (1:19) ,nineteen address line. > > can anybody explain,how it is to be done ,say for bf531. the processor doesn't matter. You want 32 bits of address space using 19 bits! The way to do that is called "bank switching", and it's been used since the dawn of computers. Use A19 to select your mux register and let it hold 32-18 = 14 upper address bits. Make any access to 0x80000 use the lower 14 data bits to set up a latch that holds the upper 14 address lines to your 4GB array. Then when you access any address in the range 0x00000 to 0x7ffff you will see into one bank of your array. With 14 bits in the latch, you will have 16k banks, and each bank will be 18 bits wide or 256k. Patience, persistence, truth, Dr. mike |
(You need to be a member of adsp -- send a blank email to adsp-subscribe@yahoogroups.com )