FAQ for FR Family
I/O
- The manual describes that the MOD pin is directly connected to Vcc and GND, but it is connected to Vcc via a resistor in the specifications of Flash Programmer. Which is correct? What is the appropriate resistance for connecting to Vcc via a pull-up resistor? (Target: MB91F155A)
- What processing is required when the oscillation pin for low-speed clock pulse is not used? (Target: MB91F133)
- Is there any interrupt pin substituting to the NMI pin? (Target: MB91F133)
- Can we specify A[23:16] individually as general port? Example: Use A[18:16] as addresses and the others as ports. (Target: MB91F155A)
The manual describes that the MOD pin is directly connected to Vcc and GND, but it is connected to Vcc via a resistor in the specifications of Flash Programmer. Which is correct? What is the appropriate resistance for connecting to Vcc via a pull-up resistor? (Target: MB91F155A)
- Answer :
It is essentially desirable to directly connect it to Vcc and GND. However, because it is affected by noise or other factors, connect a pull-up resistor of as small a value as possible.
What processing is required when the oscillation pin for low-speed clock pulse is not used? (Target: MB91F133)
- Answer :
Perform the pin processing so as to connect X0A (input) to GND and leave X1A (output) "OPEN."
Is there any interrupt pin substituting to the NMI pin? (Target: MB91F133)
- Answer :
Use an external interrupt pin.
Can we specify A[23:16] individually as general port? Example: Use A[18:16] as addresses and the others as ports. (Target: MB91F155A)
- Answer :
You can individually use each pin by the external pin control register. See page 101 of "Hardware Manual （CM71-10110-4）."
