AN1356 STMicroelectronics, AN1356 Datasheet - Page 45

• Manufacturer Part Number: AN1356
• Description: PSDSOFT EXPRESS AND PSD4235G2 DESIGN GUIDE
• Manufacturer: STMicroelectronics

AN1356 - APPLICATION NOTE
PSDsoft Express Design Entry
To implement the advanced memory maps of Figure 45 through to Figure 48, invoke PSDsoft Express ,
open the project “logicXA” from the second design example (if not already open). Now pull down the menu
‘Project’ from the top of the screen, and select ‘Save As’. For this third design example, save the second
project under the new name “advancXA”. Now click on the ‘Define PSD Pin/Node Functions’ box in the
design flow diagram. Click Next >> to get to the ‘Page Register Definition’ screen since no pin
assignments need to be changed for this third design.
Page Register Definition
You will need to define two additional PSD page register bits to be used for logic as shown below labeling
one bit “swap” and the other bit “unlock”.
Figure 49. Page Register Definition
Click Next >>.
Chip-Select Equations
The chip-select equations for PSD SRAM (rs0), PSD control registers (csiop), and the external LCD
module (lcd_e), and most of the internal PSD memory segments do not change from the second design
example. Only chip-selects for main PSD Flash memory segment fs0, and the secondary PSD Flash
memory segments csboot0 – csboot3 need to change for this third design because they are affected by
memory swapping.
These internal memory chip-selects must be qualified with the page register bit “swap” as shown below.
The secondary PSD memory segments, csboot0 and csboot1, must be additionally qualified by “unlock”
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