z86e72 ZiLOG Semiconductor, z86e72 Datasheet - Page 42

• Manufacturer Part Number: z86e72
• Description: Otp Microcontroller
• Manufacturer: ZiLOG Semiconductor

PS008704-0507
External Memory
Note:
The Z86E72/73 microcontrollers address up to 32 KB (minus FD00H–FFFFH) of
external memory beginning at address 8000H (32K+1). External data memory is
included with, or separated from, the external program memory space. /DM, an
optional I/O function that is programmed to appear on P34, is used to distinguish
between data and program memory space. The state of the /DM signal is con-
trolled by the type of instruction being executed. An LDC op code references
PROGRAM (/DM inactive) memory, and an LDE instruction references data (/DM
active Low) memory. See
The Extended Data RAM cannot be used as STACK or
instruction/code memory. Accessing the Extended Data RAM
has the following condition: P01M register bits D4–D3 cannot
be set to 11.
Figure
21.
OTP Microcontroller
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