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Semiconductor Group
32
System Reset
Figure 6-1 a) - c)
Reset Circuitries
A correct reset leaves the processor in a defined state. The program execution starts at location
0000H. The default values of the special function registers (SFR) during and after reset are listed
in table 6-1. After reset is internally accomplished the contents of the port latches of port 0 to 5 is
0FFH. This leaves port 0 floating, since it is an open drain port when not used as data/address bus.
All other I/O port lines (ports 1 through 5) output a one (1).
In the MYMOS versions, the analog input lines AN0 to AN7 can only be used as inputs.
In the ACMOS versions these lines may also be used as digital inputs. In this case they are
addressed as an additional input port (port 6) via special function register P6 (0DBH) Since port 6
has no internal latch, the contents of SFR P6 only depends on the levels applied to the input lines.
For details about this port please refer to section 7.1 (Parallel I/O).
The contents of the internal RAM of the SAB 80(C)515 is not affected by a reset. After power-up the
contents is undefined, while it remains unchanged during a reset if the power supply is not turned
off.
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Summary of Contents for SAB 80515 Series
Page 9: ...Semiconductor Group 9 Introduction Figure 1 2 Block Diagram ...
Page 12: ...Semiconductor Group 12 Fundamental Structure Figure 2 1 Detailed Block Diagram ...
Page 18: ...Semiconductor Group 18 Central Processing Unit Figure 3 1 Fetch Execute Sequence ...
Page 73: ...Semiconductor Group 73 On Chip Peripheral Components Figure 7 25 A D Converter Block Diagram ...
Page 83: ...Semiconductor Group 83 On Chip Peripheral Components Figure 7 33 a Timer 2 Block Diagram ...
Page 215: ...Device Specifications Semiconductor Group 215 ...
Page 217: ...Device Specifications Semiconductor Group 217 Pin Configuration P LCC 68 ...
Page 219: ...Device Specifications Semiconductor Group 219 Logic Symbol ...
Page 226: ...Device Specifications Semiconductor Group 226 Figure 1 Block Diagram ...
Page 229: ...Device Specifications Semiconductor Group 229 Figure 2 Memory Address Spaces ...
Page 239: ...Device Specifications Semiconductor Group 239 Figure 4 Block Diagram of the A D Converter ...
Page 241: ...Device Specifications Semiconductor Group 241 Figure 5 Interrupt Request Sources ...
Page 242: ...Device Specifications Semiconductor Group 242 Figure 6 Interrupt Priority Level Structure ...