Now my hardware connection is like this: p0.7 p0.1 p0.0 of the MCU are connected to cs A1 and A0 of 8255 through latches respectively. The hardware address I calculated is like this: D8255 EQU FF73H; ...
The working principle of the circuit of the device is shown in Figure 6. When the fuse FU1 is intact, the neon bulb ND is short-circuited and does not light up, and at the same time, the ① and ② pins ...
It takes 1.4ms from the first instruction of ISR to the first instruction of interrupt thread IST response (setting an IO output). Some friends in the forum have tested it and said it only takes 400us...