| ??? 11/29/08 15:32 Read: times |
#160414 - don't be deceived by Keil's database Responding to: ???'s previous message |
Per Westermark said:
A lot of chips that can easily be extended to 64kB XDATA. Actually, I know of NO '51 derivatives with external memory bus implemented, which could not directly MOVX-access 64kB (i.e. which would have external bus missing some address lines). There are quite a lot of those, which don't support MOVX-style external memory at all, though; usually the low-pin-count ones. Per Westermark said:
And it seems to be 14 chips in the Keil database with 64kB or more internally. Don't be deceived. The Dallas "chips" are in fact modules on a SIMM-stick. The chip itself is ROM- and XRAM-less. Mentor and Handshake (a Philips/NXP spin-off or subsidiary, with an interesting asynchronous design, but no "publicly" sold chips) offer IP, so you should read it rather as "64kB MOVX capable". This leaves the Tezzaron devices as the sole single-package solution for >64kB XRAM. The second best I know are the fatter parts of uPSD3xxx family, which come with up to 32kB of internal XRAM, together with an inordinate amount of FLASH. JW |
