Messages in this thread | | | Date | Thu, 16 Jan 2003 17:00:24 -0300 | From | Gabriel Gomiz <> | Subject | Re: NCR 7452/3 POS - Retail CMOS NVRAM Driver |
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Richard B. Johnson wrote: > On Wed, 15 Jan 2003, Gabriel Gomiz wrote: >> >>The memory chips that NCR uses are: >>1) NEC D43256BGU - NCR POS Model 7452-1011 >> The chip is 256KB, but NCR says they use only 128KB >>2) NEC D431000AGW - NCR POS Model 7453-1011 >> The chip is 1MB, but NCR says they use only 128KB >> > > Look in the ethernet drivers for the "bit-banging" routines > used to access NVRAM in the devices. You need to shift bits > in and out of these devices. They are SERIAL ERPROMS. You > can get data sheets by using your favorite search engine > (as I just did).
I grabbed the datasheets of the memory chips and found out the following, that changes the incorrect information that I had:
1) NEC D43256BGU is 256Kbits = 32KB (32768 words of 8 bits)
This chip has 15 address lines (A0-A14) and 8 data lines (I/O1 - I/O8).
2) NEC D431000AGW is 1Mbit = 128KB (131072 word of 8 bits)
This chip has 17 address lines (A0-A16) and 8 data lines (I/O1 - I/O8).
So it seems that these chips doesn't have a serial-like interface for bit-banging, I am wrong?
-- .^. Gabriel Gomiz - Red Hat Certified Engineer (RHCE) /V\ // \\ /( )\ ^^-^^ s/Window[$s]/LINUX!!/g or die;
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