SDA6000 Datasheet, PDF (74/380 Pages) Infineon Technologies AG – Teletext Decoder with Embedded 16-bit Controller

SDA 6000
C16X Microcontroller
CSP
Reset Value: 0000_H
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
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SEGNR(7..0)
--------
r
Bit
SEGNR
(7 … 0)
Function
Segment Number
Specifies the code segment, from where the current instruction is to be
fetched. SEGNR is ignored when segmentation is disabled.
Code memory addresses are generated by directly extending the 16-bit contents of the
IP register by the contents of the CSP register, as shown in Figure 4-14.
In case of the segmented memory mode the selected number of segment address bits
(via bit field SALSEL) of the CSP register is output on the respective segment address
pins of Port 4 for all external code accesses. For non-segmented memory mode the
content of this register is not significant, because all code accesses are automatically
restricted to segment 0.
Note: The CSP register can only be read but not written by data operations. It is,
however, modified either directly by means of the JMPS and CALLS instructions,
or indirectly via the stack by means of the RETS and RETI instructions.
Upon the acceptance of an interrupt or the execution of a software TRAP
instruction, the CSP register is automatically set to zero.
Users Manual
4 - 41
2000-06-15