C509-L_97 Datasheet, PDF (37/290 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

Memory Organization
C509-L
3.4.7 Operating Mode (Chipmode) Selection
The chipmode selection can be done by hardware after an active RESET or HWPD signal. Further,
the logic state of pin PRGEN is used for hardware selection. Bit Swap is not affected by hardware
selection. The chipmodes can also be selected by software. Software selection is achieved by
programming specific bits of SFR SYSCON1.
The following table 3-2 shows the hardware and software selection capabilities of the chipmodes.
Table 3-2
Hardware and Software Selection of Chipmodes
Operating Mode
(Chipmode)
Hardware Selection
Software Selection
Normal Mode
PRGEN pin = low
RESET or HWPD:
1 ^{PRGEN pin = don’t care;}
4
edge setting bits PRGEN1,SWAP = 0,0;
executing unlock sequence
XRAM Mode
from Programming Mode:
setting PRGEN pin = low
2 ^{PRGEN pin = don’t care;}
5
setting bits PRGEN1,SWAP = 0,1;
executing unlock sequence
Bootstrap Mode
PRGEN pin = high
RESET or HWPD:
3 ^{PRGEN pin = high;}
6
edge setting bits PRGEN1,SWAP =1,0;
executing unlock sequence
Programming Mode
not possible
PRGEN pin = high;
7
setting bits PRGEN1,SWAP = 1,1;
executing unlock sequence
Figure 3-7 below shows the information of table 3-2 as a state diagram (reference number in the
circle).
1
Normal Mode
PRGEN1, SWAP = 0,0
4
5
XRAM Mode
PRGEN1, SWAP = 0,1
5
2
5
6
3
4
7
6
Bootstrap Mode
PRGEN1, SWAP = 1,0
Figure 3-7
State Diagram of Chipmode Selection
Semiconductor Group
3-12
7
4
Programming Mode
PRGEN1, SWAP = 1,1
7
6
Hardware Selection
Software Selection
MCD02645
1997-10-01