For the memory system of Figure 12-36, assume that the CPU is storing one byte of data at system address 4000 (hex).

(a) Which chip is the byte stored in?

(b) Is there any other address in this system that can access this data byte?

(c) Answer parts (a) and (b) by assuming that the CPU has stored a byte at address 6007.

(d) Assume that the program is storing a sequence of data bytes in the EEPROM and that it has just completed the 2048th byte at address 67FF. If the programmer allows it to store one more byte at address 6800, what will be the effect on the first 2048 bytes?

Figure 12-36

Transcribed Image Text:

A15 A₁4 A13 A12 A10 A₂ 15 4 13 12 Control bus E 3-line-to-8-line decoder с B 74ALS138 A 1-of-8 decoder E3 CE2 Decoder selects one memory chip determined by A13-A15 R/W 01234567 50000000 60 18 [13] A₂-A₁2 PROM-0 8K X 8 07-00 [8] Address bus [16] K1 [13] A₁-A₁2 PROM-1 8K X 8 [8] Data bus [8] Address ranges (hex) 0000 to 1FFF-PROM-0 2000 to 3FFF-PROM-1 4000 to 5FFF - RAM 6000 to 67FFEEPROM K2 OCS WE [13] A₁-A12 RAM 8K X 8 V/0,-1/00 [8] K3 CS WE [11] Ao-A10 EEPROM 2K X 8 1/07-1/00 [8]