ST72361J6 STMicroelectronics, ST72361J6 Datasheet - Page 22

• Manufacturer Part Number: ST72361J6
• Description: 8-bit MCU
• Manufacturer: STMicroelectronics

Specifications of ST72361J6

• Hdflash Endurance: 100 cycles, data retention 40 years at 85°C
• 5 Power Saving Modes: Halt, Auto Wake Up From Halt, Active Halt, Wait and Slow

ST72361
6.3 RESET SEQUENCE MANAGER (RSM)
6.3.1 Introduction
The reset sequence manager includes three RE-
SET sources as shown in
■
■
■
These sources act on the RESET pin and it is al-
ways kept low during the delay phase.
The RESET service routine vector is fixed at ad-
dresses FFFEh-FFFFh in the ST7 memory map.
The basic RESET sequence consists of three
phases as shown in
■
■
■
The 256 or 4096 CPU clock cycle delay allows the
oscillator to stabilize and ensures that recovery
has taken place from the Reset state. The shorter
or longer clock cycle delay should be selected by
option byte to correspond to the stabilization time
of the external oscillator used in the application.
The RESET vector fetch phase duration is two
clock cycles.
Figure 13. Reset Block Diagram
22/225
External RESET source pulse
Internal LVD RESET (Low Voltage Detection)
Internal WATCHDOG RESET
Active Phase depending on the RESET source
256 or 4096 CPU clock cycle delay (selected by
option byte)
RESET vector fetch
RESET
Figure
V
Figure
DD
1:
R
ON
2:
Filter
Figure 12. RESET Sequence Phases
Caution: When the ST7 is unprogrammed or fully
erased, the Flash is blank and the RESET vector
is not programmed. For this reason, it is recom-
mended to keep the RESET pin in low state until
programming mode is entered, in order to avoid
unwanted behavior.
6.3.2 Asynchronous External RESET pin
The RESET pin is both an input and an open-drain
output with integrated R
This pull-up has no fixed value but varies in ac-
cordance with the input voltage. It can be pulled
low by external circuitry to reset the device. See
Electrical Characteristic section for more details.
A RESET signal originating from an external
source must have a duration of at least t
order to be recognized (see
tion is asynchronous and therefore the MCU can
enter reset state even in HALT mode.
GENERATOR
PULSE
Active Phase
256 or 4096 CLOCK CYCLES
INTERNAL RESET
RESET
ON
weak pull-up resistor.
Figure
WATCHDOG RESET
LVD RESET
INTERNAL
RESET
3). This detec-
VECTOR
h(RSTL)in
FETCH
in