OWRDBIT Pin, Bit Var

Function
Reads one bit from a 1-Wire bus.

Quick Facts
  All SX Models
 Special Notes  The DQ pin (specified by Pin) must have a 4.7 kΩ pull-up resister.
 1-Wire commands require a FREQ setting of 4 MHz or higher.

Explanation
Some 1-Wire transactions require reading data from the device. While this is typically handled with OWRDBYTE, SX/B supports bit access with the OWRDBIT instruction. A 1-Wire read is accomplished by generating a brief (5 µS) low-pulse and sampling the DQ pin within 15 µS of the falling edge of the pulse. This is called a "Read Slot." The diagram and table below details the Read Slot sequence generated by the SX with OWRDBIT.

Note Timing  Description
A 5 µS  Initiate Read Slot (SX master)
B 10 µS  Delay before sampling DQ
C ~ 60 µS  Read Slot recovery


Related instructions: OWRESET, OWRDBYTE, OWWRBIT, and OWWRBYTE