C8051F331-GMR Silicon Laboratories Inc, C8051F331-GMR Datasheet - Page 94

• Manufacturer Part Number: C8051F331-GMR
• Description: IC 8051 MCU 8K FLASH 20QFN
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F33xr

Specifications of C8051F331-GMR

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 17
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-QFN
• For Use With: 336-1451 - ADAPTER PROGRAM TOOLSTICK F330336-1264 - DEV KIT FOR C8051F330/F331
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

10. Reset Sources
Reset circuitry allows the controller to be easily placed in a predefined default condition. On entry to this
reset state, the following occur:
•
•
•
•
All SFRs are reset to the predefined values noted in the SFR detailed descriptions. The contents of internal
data memory are unaffected during a reset; any previously stored data is preserved. However, since the
stack pointer SFR is reset, the stack is effectively lost, even though the data on the stack is not altered.
The Port I/O latches are reset to 0xFF (all logic ones) in open-drain mode. Weak pullups are enabled dur-
ing and after the reset. For VDD Monitor and power-on resets, the RST pin is driven low until the device
exits the reset state.
On exit from the reset state, the program counter (PC) is reset, and the system clock defaults to the inter-
nal oscillator. Refer to
the system clock source. The Watchdog Timer is enabled with the system clock divided by 12 as its clock
source
Program execution begins at location 0x0000.
Px.x
Px.x
CIP-51 halts program execution
Special Function Registers (SFRs) are initialized to their defined reset values
External Port pins are forced to a known state
Interrupts and timers are disabled.
(Section “19.3. Watchdog Timer Mode” on page 201
System
Clock
Comparator 0
+
-
Section “13. Oscillators” on page 113
Detector
Missing
C0RSEF
Clock
(one-
shot)
Microcontroller
EN
CIP-51
Core
Figure 10.1. Reset Sources
WDT
PCA
EN
VDD
System Reset
Supply
Monitor
+
-
Rev. 1.7
Enable
(Software Reset)
SWRSF
for information on selecting and configuring
C8051F330/1/2/3/4/5
details the use of the Watchdog Timer).
'0'
Power On
Reset
Operation
FLASH
Errant
(wired-OR)
Reset
Funnel
/RST
97