External Reset Pin; Figure 3.5-1 Block Diagram Of External Reset Pin - Fujitsu F2MC-8L Series Hardware Manual

3.5.1

External Reset Pin

Inputting an "L" level to the external reset pin generates a reset. If products are set to
with the reset output (optional), the pin outputs an "L" level depending on internal
reset sources.
Block Diagram of External Reset Pin
The external reset pin (RST) on products with the reset output is a hysteresis input type and N-
ch open-drain output type with a pull-up resistor.
The external reset pin on products without a reset output option is only for the reset input.
Figure 3.5-1 shows the block diagram of the external reset pin.
RST
Pin
External Reset Pin Functions
Inputting an "L" level to the external reset pin (RST) generates an internal reset signal.
On products with the reset output, the pin outputs an "L" level depending on internal reset
sources or during the oscillation stabilization delay time due to a reset. Software reset,
watchdog reset, and power-on reset are classed as internal reset sources.
Check:
The external reset inputs are accepted independently of and asynchronously with the
internal clock.
Initialization of the internal circuit requires a clock. Especially when an external clock is used,
a clock is needed to be input at the reset.

Figure 3.5-1 Block Diagram of External Reset Pin

Pull-up resistor
Approx. 50 k /5.0V
Option
P-ch
With reset output
Without reset output
N-ch
Internal reset signal
Input buffer
Internal reset source
3.5 Resets
55