ST10R172LT1 STMicroelectronics, ST10R172LT1 Datasheet - Page 25

• Manufacturer Part Number: ST10R172LT1
• Description: MCU 16BIT ROMLESS LV 100TQFP
• Manufacturer: STMicroelectronics
• Series: ST10r

Specifications of ST10R172LT1

• Core Processor: ST10
• Core Size: 16-Bit
• Speed: 50MHz
• Connectivity: EBI/EMI, SSP, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 77
• Program Memory Type: ROMless
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 100-TQFP, 100-VQFP
• Controller Family/series: ST10
• No. Of I/o's: 77
• Ram Memory Size: 1KB
• Cpu Speed: 50MHz
• No. Of Timers: 5
• Embedded Interface Type: SPI, USART
• No. Of Pwm Channels: 1
• Rohs Compliant: Yes
• Processor Series: ST10R1x
• Core: ST10
• Data Bus Width: 16 bit
• Data Ram Size: 1 KB
• Interface Type: SSP, USART
• Maximum Clock Frequency: 50 MHz
• Number Of Programmable I/os: 77
• Number Of Timers: 5
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• On-chip Adc: 8 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: In Transition

ST10R172L - SYSTEM RESET
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SYSTEM RESET
The following type of reset are implemented on the ST10R172L:
Asynchronous hardware reset: Asynchronous reset does not require a stabilized clock
signal on XTAL1 as it is not internally resynchronized, it resets the microcontroller into its
default reset state. Asynchronous reset is required on chip power-up and can be used during
catastrophic situations. The rising edge of the RSTIN pin is internally resynchronized before
exiting the reset condition, therefore, only the entry to hardware reset is asynchronous.
Synchronous hardware reset (warm reset): A warm synchronous hardware reset is
triggered when the reset input signal RSTIN is latched low and Vpp pin is high. The I/Os are
immediately (asynchronously) set in high impedance, RSTOUT is driven low. After RSTIN
negation is detected, a short transition period elapses, during which pending internal hold
states are cancelled and any current internal access cycles are completed, external bus
cycles are aborted. Then, the internal reset sequence is active for 1024 TCL (512 CPU clock
cycles). During this reset sequence, if bit BDRSTEN was previously set by software (bit 3 in
SYSCON register), RSTIN pin is driven low and internal reset signal is asserted to reset the
microcontroller in its default state. Note that after all reset sequence, bit BDRSTEN is cleared.
After the reset sequence has been completed, the RSTIN input is sampled. When the reset
input signal is active at that time the internal reset condition is prolonged until RSTIN
becomes inactive.
Software reset: The reset sequence can be triggered at any time by the protected
instruction SRST (software reset). This instruction can be executed deliberately within a
program, e.g. to leave bootstrap loader mode, or on a hardware trap that reveals a system
failure. As for a synchronous hardware reset, if bit BDRSTEN was previously set by software
(bit 3 in SYSCON register), the reset sequence lasts 1024 TCL (512 CPU clock cycles), and
drives the RSTIN pin low.
Watchdog timer reset: When the watchdog timer is not disabled during the initialization or
serviced regularly during program execution it will overflow and trigger the reset sequence.
Unlike hardware and software resets, the watchdog reset completes a running external bus
cycle if this bus cycle does not use READY, or if READY is sampled active (low) after the
programmed waitstates. When READY is sampled inactive (high) after the programmed
waitstates the running external bus cycle is aborted. Then the internal reset sequence is
started. The watchdog reset cannot occur while the ST10R172L is in bootstrap loader mode.
Bidirectional reset: The bidirectional reset is activated by setting bit BDRSTEN (bit 3 in
SYSCON register). This reset makes the watchdog timer reset and software reset externally
visible. It is active for the duration of an internal reset sequences caused by a watchdog timer
reset and software reset. Therefore, the bidirectional reset transforms an internal watchdog
timer reset or software reset into an external hardware reset with a minimum duration of
1024 TCL.
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