Z51F0410 Datasheet, PDF (45/184 Pages) Zilog, Inc. – Z8051 Series 8-Bit Microcontrollers

Z51F0410
Product Specification
2. Functional Description
2.1 Memory
The Z51F0410 MCU addresses two separate address memory stores: Program memory and Data
memory. The logical separation of Program and Data memory allows Data memory to be assessed by
8-bit addresses, which can be more quickly stored and manipulated by 8-bit CPU. Nevertheless, 16-
bit Data memory addresses can also be generated through the DPTR register.
Program memory can only be read, not written to. There can be up to 64K bytes of Program
memory. In the Z51F0410 Flash version of these devices the 4K bytes of Program memory are
provided on-chip. Data memory can be read and written to up to 256 bytes internal memory (DATA)
including the stack area.
2.1.1 Program Memory
A 16-bit program counter is capable of addressing up to 64K bytes, but this device has just 4K bytes
program memory space.
Figure 2.1 shows a map of the lower part of the program memory. After reset, the CPU begins
execution from location 0000H. Each interrupt is assigned a fixed location in program memory. The
interrupt causes the CPU to jump to that location, where it commences execution of the service
routine. External interrupt 0, for example, is assigned to location 000BH. If external interrupt 0 is going
to be used, its service routine must begin at location 000BH. If the interrupt is not going to be used, its
service location is available as general purpose program memory. If an interrupt service routine is
short enough (as is often the case in control applications), it can reside entirely within that 8 byte
interval. Longer service routines can use a jump instruction to skip over subsequent interrupt
locations, if other interrupts are in use.
FFFFH
0FFFH
0000H
4KBytes
- User Function Mode: 4KBytes IncludFeigduInrete2rr.u1pPt rVoegcrtaomr Rmegeimonory
- Nonvolatile and reprogramming memory: Flash memory based on EEPROM cell
2.1.2 Data Memory
Figure 2.2 shows the internal Data memory space available.
PS029502-0212
PRELIMINARY
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