E
Ed
- Jan 1, 1970
- 0
I have a circuit using a DS89C450 micro and an external 1m(128kx8)ROM.
I am using P1.0 as an upper address bit which is low for this test.
I have /CE tied low and use /OE derived from p3.7(/rd) to read from the ROM.
When I do a movx a,@dptr /OE does go low and about 10ns later the data
becomes valid but goes away after 30ns.
Shouldn't the data be valid throughout the entire /OE ?
When I send the data I received to the serial port, it was 00h and not what
I saw for the 30ns but what was after the 30ns.
I have msg'd the manufacturers tech support also.
Any ideas?
I am using P1.0 as an upper address bit which is low for this test.
I have /CE tied low and use /OE derived from p3.7(/rd) to read from the ROM.
When I do a movx a,@dptr /OE does go low and about 10ns later the data
becomes valid but goes away after 30ns.
Shouldn't the data be valid throughout the entire /OE ?
When I send the data I received to the serial port, it was 00h and not what
I saw for the 30ns but what was after the 30ns.
I have msg'd the manufacturers tech support also.
Any ideas?