sak-c868p-1rr Infineon Technologies Corporation, sak-c868p-1rr Datasheet - Page 27

• Manufacturer Part Number: sak-c868p-1rr
• Description: 8 - Bit Cmos Microcontroller
• Manufacturer: Infineon Technologies Corporation

Reset initializes the stack pointer to location 07
location 08
to use more than one register bank, the SP should be initialized to a different location of
the RAM which is not used for data storage.
3.3
The C868 can operate in four different operating modes (chipmodes) with different
program and data memory organisations:
3.3.1
There are four control bits located in SFR SYSCON1 which control the code and data
memory organisation of the C868. Two of these bits (BSLEN and SWAP) cannot be
programmed as normal bits but with a special software unlock sequence. The special
software unlock sequence was implemented to prevent unintentional changing of these
bits and consists of consecutive followed instructions which have to set set two
dedicated enable bits.
SYSCON1
System Control Register 1
Field
SWAP
User’s Manual
ESWC
– Normal Mode
– Normal XRAM Mode
– Bootstrap Mode
– Bootstrap XRAM Mode
w
7
H
Program and Data Memory Organisation
Special function register SYSCON1
which is also the first register (R0) of register bank 1. Thus, if one is going
SWC
w
6
Bits
0
5
-
r
Typ Description
rw
SWAP Code and Data Memory
SWAP = 0 : Code and data memory are in their standard
locations (default)
SWAP = 1 : Code and data memory are swapped
The modification of this bit is by software only and must be
completed by the special software unlock sequence in
order to effect the mode change. Otherwise, this bit
automatically reverts to its previous value with the third EOI
(end of instruction) after this bit is modified. This is to
prevent any incorrect status read.
4
-
r
3-3
H
3
-
r
and increments it once to start from
BSLEN
rw
[Reset value: 00XXX0X0
2
Memory Organization
1
-
r
V 1.0, 2003-01
SWAP
rw
C868
0
B
]