C8051F901-GU Silicon Laboratories Inc, C8051F901-GU Datasheet - Page 145

• Manufacturer Part Number: C8051F901-GU
• Description: IC MCU 8BIT 8KB FLASH 24QSOP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F9xxr

Specifications of C8051F901-GU

• Program Memory Type: FLASH
• Program Memory Size: 8KB (8K x 8)
• Package / Case: 24-QSOP
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 16
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 0.9 V ~ 3.6 V
• Data Converters: A/D 15x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: C8051F9x
• Core: 8051
• Data Ram Size: 768 B
• Interface Type: UART
• Maximum Clock Frequency: 25 MHz
• Number Of Timers: 4
• Operating Supply Voltage: 0.9 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F912DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Package: 24QSOP
• Device Core: 8051
• Family Name: C8051F90x
• Maximum Speed: 25 MHz
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 16
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1847-5

14.2. Idle Mode
Setting the Idle Mode Select bit (PCON.0) causes the CIP-51 to halt the CPU and enter Idle mode as soon
as the instruction that sets the bit completes execution. All internal registers and memory maintain their
original data. All analog and digital peripherals can remain active during Idle mode.
Note: To ensure the MCU enters a low power state upon entry into Idle Mode, the one-shot circuit should be
Idle mode is terminated when an enabled interrupt is asserted or a reset occurs. The assertion of an
enabled interrupt will cause the Idle Mode Selection bit (PCON.0) to be cleared and the CPU to resume
operation. The pending interrupt will be serviced and the next instruction to be executed after the return
from interrupt (RETI) will be the instruction immediately following the one that set the Idle Mode Select bit.
If Idle mode is terminated by an internal or external reset, the CIP-51 performs a normal reset sequence
and begins program execution at address 0x0000.
If enabled, the Watchdog Timer (WDT) will eventually cause an internal watchdog reset and thereby termi-
nate the Idle mode. This feature protects the system from an unintended permanent shutdown in the event
of an inadvertent write to the PCON register. If this behavior is not desired, the WDT may be disabled by
software prior to entering the idle mode if the WDT was initially configured to allow this operation. This pro-
vides the opportunity for additional power savings, allowing the system to remain in the idle mode indefi-
nitely, waiting for an external stimulus to wake up the system. Refer to Section “18.6. PCA Watchdog Timer
Reset” on page 176 for more information on the use and configuration of the WDT.
14.3. Stop Mode
Setting the Stop Mode Select bit (PCON.1) causes the CIP-51 to enter stop mode as soon as the instruc-
tion that sets the bit completes execution. In stop mode the precision internal oscillator and CPU are
stopped; the state of the low power oscillator and the external oscillator circuit is not affected. Each analog
peripheral (including the external oscillator circuit) may be shut down individually prior to entering stop
mode. Stop mode can only be terminated by an internal or external reset. On reset, the CIP-51 performs
the normal reset sequence and begins program execution at address 0x0000.
If enabled, the Missing Clock Detector will cause an internal reset and thereby terminate the Stop mode.
The Missing Clock Detector should be disabled if the CPU is to be put to in STOP mode for longer than the
MCD timeout.
Stop mode is a legacy 8051 power mode; it will not result in optimal power savings. Sleep or suspend
mode will provide more power savings if the MCU needs to be inactive for a long period of time.
Note: To ensure the MCU enters a low power state upon entry into Stop Mode, the one-shot circuit should be
enabled by clearing the BYPASS bit (FLSCL.6).
enabled by clearing the BYPASS bit (FLSCL.6).
Rev. 1.0
C8051F91x-C8051F90x
145