EFM32G200F64 Energy Micro, EFM32G200F64 Datasheet - Page 289

• Manufacturer Part Number: EFM32G200F64
• Description: MCU 32BIT 64KB FLASH 32-QFN
• Manufacturer: Energy Micro
• Series: Geckor

Specifications of EFM32G200F64

• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 32MHz
• Connectivity: EBI/EMI, I²C, IrDA, SmartCard, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 24
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.8 V
• Data Converters: A/D 4x12b, D/A 1x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad
• Processor Series: EFM32G200
• Core: ARM Cortex-M3
• Data Bus Width: 32 bit
• Data Ram Size: 16 KB
• Interface Type: I2C, UART
• Maximum Clock Frequency: 32 MHz
• Number Of Programmable I/os: 24
• Number Of Timers: 2
• Operating Supply Voltage: 1.8 V to 3.8 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

21.3.3.2.3 Buffered Mode
2010-09-06 - d0001_Rev1.00
Figure 21.3. LETIMER One-shot Repeat State Machine
The Buffered repeat mode allows buffered timer operation. When started, the timer runs
LETIMERn_REP0 number of times. If LETIMERn_REP1 has been written since the last time it was used
and it is nonzero, LETIMERn_REP1 is then loaded into LETIMERn_REP0, and counting continues the
new number of times. The timer keeps going as long as LETIMERn_REP1 is updated with a nonzero
value before LETIMERn_REP0 is finished counting down.
If the timer is started when both LETIMERn_CNT and LETIMERn_REP0 are zero but LETIMERn_REP1
is non-zero, LETIMERn_REP1 is loaded into LETIMERn_REP0, and the counter counts the loaded
number of times. The state machine for the one-shot repeat mode is shown in Figure 21.3 (p. 289) .
Used in conjunction with a buffered top value, enabled by setting BUFTOP in LETIMERn_CTRL, the
buffered mode allows buffered values of both the top and repeat values of the timer, and the timer can
for instance be set to run 4 times with period 7 (top value 6), 6 times with period 200, then 3 times with
period 50.
A state machine for the buffered repeat mode is shown in Figure 21.4 (p. 290) . REP1
state machine is an internal variable that keeps track of whether the value in LETIMERn_REP1 has been
loaded into LETIMERn_REP0 or not. The purpose of this is that a value written to LETIMERn_REP1
should only be counted once. REP1
CNT = CNT - 1
CNT = TOP*
NO
NO
NO
REP0 = = 0
CNT = = 0
START
YES
YES
YES
If (COMP0TOP)
Else
TOP*
USED
TOP* = COMP0
TOP* = 0xFFFF
is cleared whenever LETIMERn_REP1 is written.
NO
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289
RUNNING
CNT = = 0
REP0 < 2
YES
YES
YES
Wait for positive clock edge
NO
TOP* *
If (! COMP0TOP)
Else if (COMPBUF)
Else
NO
TOP* * = 0xFFFF
TOP* * = COMP1
TOP* * = COMP0
CNT = CNT - 1
CNT = TOP*
If (! START)
STOP = 1
REP0 = 0
REP0 = REP0 - 1
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USED
If (STOP)
Else if (START)
End if
START = 0
STOP = 0
shown in the
RUNNING = 0
RUNNING = 1