Fig. 1.8 Undefined-Value Output Timing Chart - Fujitsu MB90420/5 (A) Series Hardware Manual

MB90420/5 (A) SERIES F
• Input sequence of power analog input of A/D converter
Apply the digital power (V
inputs (AN0 to AN7) for the A/D converter. Disconnect the power supply and analog inputs for the A/D
converter first, and then disconnect the digital power (V
Also, do not allow the input voltage to exceed AV
an input port (Simultaneous application and disconnection of analog power and digital power is allowed).
• Pull-up/-down resistor
The MB90420/5 (A) series does not support internal pull-up/-down resistors. Use external components if
necessary.
• Output of undefined values from port at power-on reset
At a power-on reset after power-on, undefined values are output from port 0/1. Note the following timing of
undefined values:
V (Power pin)
CC
PONR (Power-on reset) signal
RSTX (External asynchronous reset) signal
RST (Internal reset) signal
Oscillation clock signal
KA (Internal operating clock A) signal
KB (Internal operating clock B) signal
PORT (Port output) signal
(1) At power-on: Original oscillation × 2
(2) Oscillation stabilization waiting time: Original oscillation × 2
= 16 MHz)
2
MC-16LX FAMILY 16-BIT MICROCONTROLLERS HARDWARE MANUAL
, AVRH, AVRL) first, and then impress the power supply (AV
CC
Undefined-value output period

Fig. 1.8 Undefined-value Output Timing Chart

17
period (8.192 ms when original oscillation = 16 MHz)
) (At this point, AVRH must not exceed AV
CC
even when using a pin shared with an analog input as
CC
(2) Oscillation stabilization waiting time
(1) During PONR
18
period (16.384 ms when original oscillation
1-18
) and analog
CC
).
CC