AT43USB320A_04 ATMEL [ATMEL Corporation], AT43USB320A_04 Datasheet - Page 23

• Manufacturer Part Number: AT43USB320A_04
• Description: Full-speed USB Microcontroller with an Embedded Hub
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 6. Reset Logic
Power-on Reset
1443E–USB–4/04
System Clock
RSTN
VCC
Watchdog Timer
Table 7. Number of Watchdog Oscillator Cycles
A Power-on Reset (POR) circuit ensures that the device is reset from power-on. An internal
timer clocked from the Watchdog timer oscillator prevents the MCU from starting until after a
certain period after V
rise time.
If the build-in start-up delay is sufficient, RESET can be connected to V
external pull-up resistor. By holding the pin low for a period after V
Power-on Reset period can be extended.
Reset Ckt
POR Ckt
FSTRT
Programmed
Unprogrammed
Divider
CC
USB Reset
has reached the power-on threshold voltage, regardless of the V
14-bit Cntr
1.1 ms
Time-out at V
16.0 ms
OR
CC
= 5V
Cntr Reset
FSTRT
Number of WDT cycles
1K
16K
AT43USB320A
CC
has been applied, the
S
R
CC
directly or via an
ON
23
CC