How can I interface P89LPC932 @ 3V and SJA1000 @ 5V ? Can output of P89LPC932 drives input of SJA1000 , /CS /RD /WR /ALE directly ? I use P0 port of P89LPC932 as Data Bus between LPC932 and SJA1000. can they drive each other ? Can /int pin of SJA1000 drives LPC932 ? SJA1000 uses Power Up Reset, So /rst doesnt consider. Thx for advice.
Although the LPC932 is a 3 V device most of the pins are 5 V-tolerant. If 5 V is applied to a pin configured in quasi-bidirectional mode, there will be a current flowing from the pin to VDD causing extra power consumption. Therefore, applying 5 V to pins configured in quasi-bidirectional mode is discouraged.
Open drain output configuration The open drain output configuration turns off all pull-ups and only drives the pulldown transistor of the port pin when the port latch contains a logic 0. To be used as a logic output, a port configured in this manner must have an external pull-up, typically a resistor tied to VDD. The pulldown for this mode is the same as for the quasi-bidirectional mode.
Dual thread, answered in parallel thread. I wish, these doubles could be eradicated it is darn confooosing when two identical threads exist. Erik