C8051F312-GQ Silicon Laboratories Inc, C8051F312-GQ Datasheet - Page 102
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C8051F312-GQ
Manufacturer Part Number
C8051F312-GQ
Description
IC 8051 MCU 8K FLASH 32LQFP
Manufacturer
Silicon Laboratories Inc
Series
C8051F31xr
Specifications of C8051F312-GQ
Program Memory Type
FLASH
Program Memory Size
8KB (8K x 8)
Package / Case
32-LQFP
Core Processor
8051
Core Size
8-Bit
Speed
25MHz
Connectivity
SMBus (2-Wire/I²C), SPI, UART/USART
Peripherals
POR, PWM, Temp Sensor, WDT
Number Of I /o
29
Ram Size
1.25K x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 3.6 V
Data Converters
A/D 21x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Processor Series
C8051F3x
Core
8051
Data Bus Width
8 bit
Data Ram Size
1.25 KB
Interface Type
I2C, SMBus, SPI, UART
Maximum Clock Frequency
25 MHz
Number Of Programmable I/os
29
Number Of Timers
4 bit
Operating Supply Voltage
2.7 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
C8051F310DK
Minimum Operating Temperature
- 40 C
On-chip Adc
10 bit, 21 Channel
No. Of I/o's
29
Ram Memory Size
1280Byte
Cpu Speed
25MHz
No. Of Timers
4
Rohs Compliant
Yes
Package
32LQFP
Device Core
8051
Family Name
C8051F31x
Maximum Speed
25 MHz
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
For Use With
336-1445 - ADAPTER PROGRAM TOOLSTICK F310
Eeprom Size
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Other names
336-1255
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
C8051F312-GQ
Manufacturer:
Silicon Laboratories Inc
Quantity:
10 000
Company:
Part Number:
C8051F312-GQR
Manufacturer:
Silicon Laboratories Inc
Quantity:
10 000
C8051F310/1/2/3/4/5/6/7
8.4.
Power Management Modes
The CIP-51 core has two software programmable power management modes: Idle and Stop. Idle mode
halts the CPU while leaving the peripherals and clocks active. In Stop mode, the CPU is halted, all inter-
rupts and timers (except the Missing Clock Detector) are inactive, and the internal oscillator is stopped
(analog peripherals remain in their selected states; the external oscillator is not effected). Since clocks are
running in Idle mode, power consumption is dependent upon the system clock frequency and the number
of peripherals left in active mode before entering Idle. Stop mode consumes the least power. SFR Defini-
tion 8.12 describes the Power Control Register (PCON) used to control the CIP-51's power management
modes.
Although the CIP-51 has Idle and Stop modes built in (as with any standard 8051 architecture), power
management of the entire MCU is better accomplished by enabling/disabling individual peripherals as
needed. Each analog peripheral can be disabled when not in use and placed in low power mode. Digital
peripherals, such as timers or serial buses, draw little power when they are not in use. Turning off the oscil-
lators lowers power consumption considerably; however, a reset is required to restart the MCU.
8.4.1. 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.
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 “9.6. PCA Watchdog
Timer Reset” on page 108
for more information on the use and configuration of the WDT.
Note: Any instruction that sets the IDLE bit should be immediately followed by an instruction that
has 2 or more opcode bytes. For example:
// in 'C':
PCON |= 0x01; // set IDLE bit
PCON
= PCON; // ... followed by a 3-cycle dummy instruction
; in assembly:
ORL PCON, #01h ; set IDLE bit
MOV PCON, PCON; ... followed by a 3-cycle dummy instruction
If the instruction following the write of the IDLE bit is a single-byte instruction and an interrupt occurs during
the execution phase of the instruction that sets the IDLE bit, the CPU may not wake from IDLE mode when
a future interrupt occurs.
102
Rev. 1.7