AN1154 STMicroelectronics, AN1154 Datasheet - Page 20

• Manufacturer Part Number: AN1154
• Description: 8031-PSD DESIGN TUTORIAL
• Manufacturer: STMicroelectronics

AN1154 - APPLICATION NOTE
Figure 15. Simulation Results
PSDsoft Configuration
The M88 FLASH+PSD has a programmable MCU bus interface, and is able to interface directly to many
microcontrollers. Using PSD Configuration, you can specify how to interface to the MCU you have chosen
for your design. You can also configure functions specific to the PSD device you are using. This tutorial
design is based on the Intel 80C31 microcontroller, which has an 8-bit multiplexed bus with RD, WR, and
PSEN as the control signals, and an active-high level address latch enable (ALE).
To perform the configuration, take the following steps:
1. Pull down the PSDsoft menu in the main PSDsoft window and choose PSD Configuration, click the
2. Set up the global configuration as shown in Figure 16. Ensure 8-Bit is selected under “Data Bus Width”,
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“Configuration” button or click on “Device Config” in the “PSDsoft Design Flow” window. A dialog box
opens entitled “The Global Configuration”, as shown in Figure 16. Make sure the “MCU Bus
Configuration” tab is selected.
Mux is selected under “Address/Data Mode”, High is selected under “Address Latch/Strobe Setup”,
the “Enable Chip-Select Input (CSI)” box is not checked, the WR, RD, PSEN is selected under “Control
Setting”, Data Space is selected under “Flash”, and Program Space is checked under “EEPROM”.
This arrangement for program and data space allows the MCU to boot from EEPROM in the program
space, and to download to Flash memory in the data space, if needed. Afterwards, the MCU can
override this arrangement if, for example, the Flash memory needs to become part of the program
space. This can be done by the MCU writing the VM register.
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