Recently I have develop a simple 8052 board with Eprom as my external memory from 0000H address. After ordering samples from Dallas semiconductor, I've got DS1230Y NV sram which consist 32X8 bits memory.

with few changes from Eprom M27C256 from ST in connection, I manage to replace the Eprom with DS1230Y.

Recently I receive DS1230AB. But the NVsram can't function as DS1230Y does. I knew is the operating voltage between this 2 is juz AB=5% and Y=10% tolerate. But DS1230AB can't use for my bootloader to initialize my 8052 board. DS1230Y can.

So I replace again with BQ series of NV sram from Texas Instrument. BQ4011 series. Disappointed again. It can't run as Eprom or DS1230Y does.

Is it because BQ series can't be use as program code? The BQ4011 series is same, 32X8 Bits, 10% voltage tolerate.

My test is running on RS232 with MAX232CPE and Terminal program from BRAD which is under baud rate of 4800bps, programmed Steve's Bootloader boot3.hex at starting address of 0000h.

Thanks buddY!