SAB80C517-M16 SIEMENS [Siemens Semiconductor Group], SAB80C517-M16 Datasheet - Page 16

• Manufacturer Part Number: SAB80C517-M16
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Address Space
Lower 128 bytes of RAM
Upper 128 bytes of RAM
Special function registers
For details about the addressing modes see chapter 9.1.
Figure 4-1
Program Memory Address Space
The lower 128 bytes of the internal RAM are again grouped in three address spaces
(see figure 4-3):
1)
2)
3)
Semiconductor Group
A general purpose register area occupies locations 0 trough 1F H (see also section 4.3).
The next 16 bytes, locations 20 H through 2F H , contain 128 directly addressable bits.
(Programming information: These bits can be referred to in two ways, both of which are
acceptable for the ASM51. One way is to refer to their addresses, i.e. 0 to 7F H . The other way
is with reference to bytes 20 H to 2F H . Thus bits 0 to 7 can also be referred to as bits 20.0-20.7,
and bits 8-0F H are the same as 21.0-21.7 and so on. Each of the 16 bytes in this segment may
also be addressed as a byte.)
Locations 30 H to 7F H can be used as a scratch pad area.
Locations
00 H to 7F H
80 H to 0FF H
80 H to 0FF H
17
Addressing Mode
direct/indirect
indirect
direct
Memory Organization