Read Test

[seanshpark]

Read test.

0/ MCP23017 Reset will go all ports to H

1/ Power-up sequence

• Vcc -> +5V
• GND -> 0
• RST -> 0 ==>> GPB0: H, GPB1: H
• XTAL1 -> L ==>> GPB6: L

3/ Set mode to Read Mode	RST/VPP	P3.2	P3.3	P3.4	P3.5	P3.7
	GPB0:L, GPB1:H	GPB2	GPB3	PGB4	GPB5	GPB7
Read	+5V	H	L	L	H	H

3/ Read data from GPA0~GPA7

4/ Advance address

• Give pulse to XTAL1
• GPB6 H -> delay -> GPB6 L

5/ Repeat

6/ Power-off sequence

• XTAL1 -> L ==>> GPB6: L
• RST -> 0 ==>> GPB0: H, GPB1: H
• Vcc -> 0

[seanshpark]

How to compare with hex output of sdcc ?

• convert hex to bin with hex2bin
  • from https://sourceforge.net/projects/hex2bin/
  • need to build from source

[seanshpark]

done, https://github.com/seanshpark/rpigpio2/blob/main/app/at89c2051/read_test.js