AN1154 STMicroelectronics, AN1154 Datasheet - Page 63

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

AN1154 - APPLICATION NOTE
begin
#20 ale = 1;//Latch the address lines
#20 adio = addr_bus;//Read the valid address (adio defined in .top file)
#20 ale = 0;//Ale inactive
#20 adio[7:0] = data_in;//Write operation
#40 wr = 0;//Write pulse
#100 wr = 1;//Write ends
#10 adio[7:0] = Z8;//Z16 defined in .top file
end
endtask
//The "read task" implements the 80C31 read bus cycle timing
task read;
input [15:0] addr_bus;
begin
#20 ale = 1;//Latch the address lines
#20 adio = addr_bus;//Read the valid address
#20 ale = 0;//Ale inactive
#20 adio[7:0] = Z8;//Float address bus (Z8 defined in .top)
#40 rd = 0;//Read pulse
#100 rd = 1;//Read ends
end
endtask
//The "psen task" implements the 80C31 psen program fetch bus cycle
task psen;
input [15:0] addr_bus;
begin
#20 ale = 1;//Latch the address lines
#20 adio = addr_bus;//Set-up the right address
#20 ale = 0;//Ale inactive
#20 adio[7:0] = Z8;//Float address bus
#40 psen = 0;//Read pulse
#100 psen = 1;//Read ends
end
63/83