DSPIC33FJ12MC202-I/ML Microchip Technology, DSPIC33FJ12MC202-I/ML Datasheet - Page 208

• Manufacturer Part Number: DSPIC33FJ12MC202-I/ML
• Description: IC DSPIC MCU/DSP 12K 28QFN
• Manufacturer: Microchip Technology
• Series: dsPIC™ 33Fr

Specifications of DSPIC33FJ12MC202-I/ML

• Core Processor: dsPIC
• Core Size: 16-Bit
• Speed: 40 MIPs
• Connectivity: I²C, IrDA, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, Motor Control PWM, QEI, POR, PWM, WDT
• Number Of I /o: 21
• Program Memory Size: 12KB (12K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 6x10b/12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Core Frequency: 40MHz
• Core Supply Voltage: 2.75V
• Embedded Interface Type: I2C, JTAG, SPI, UART
• No. Of I/o's: 21
• Flash Memory Size: 12KB
• Supply Voltage Range: 3V To 3.6V
• Package: 28QFN EP
• Device Core: dsPIC
• Family Name: dSPIC33
• Maximum Speed: 40 MHz
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 16 Bit
• Number Of Programmable I/os: 21
• Interface Type: I2C/SPI/UART
• On-chip Adc: 6-chx10-bit|6-chx12-bit
• Number Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164336 - MODULE SOCKET FOR PM3 28/44QFNDM240001 - BOARD DEMO PIC24/DSPIC33/PIC32
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

dsPIC33FJ12MC201/202
21.4
For dsPIC33FJ12MC201/202 devices, the WDT is
driven by the LPRC oscillator. When the WDT is
enabled, the clock source is also enabled.
21.4.1
The nominal WDT clock source from LPRC is 32 kHz.
This feeds a prescaler than can be configured for either
5-bit (divide-by-32) or 7-bit (divide-by-128) operation.
The prescaler is set by the WDTPRE Configuration bit.
With a 32 kHz input, the prescaler yields a nominal
WDT time-out period (T
4 ms in 7-bit mode.
A variable postscaler divides down the WDT prescaler
output and allows for a wide range of time-out periods.
The postscaler is controlled by the WDTPOST<3:0>
Configuration bits (FWDT<3:0>), which allow the selec-
tion of 16 settings, from 1:1 to 1:32,768. Using the pres-
caler and postscaler, time-out periods ranging from
1 ms to 131 seconds can be achieved.
The WDT, prescaler, and postscaler are reset:
• On any device Reset
• On the completion of a clock switch, whether
• When a PWRSAV instruction is executed
• When the device exits Sleep or Idle mode to
• By a CLRWDT instruction during normal execution
FIGURE 21-2:
DS70265D-page 206
All Device Resets
Transition to New Clock Source
Exit Sleep or Idle Mode
PWRSAV Instruction
CLRWDT Instruction
SWDTEN
FWDTEN
LPRC Clock
invoked by software (i.e., setting the OSWEN bit
after changing the NOSC bits) or by hardware
(i.e., Fail-Safe Clock Monitor)
(i.e., Sleep or Idle mode is entered)
resume normal operation
Note:
Watchdog Timer (WDT)
PRESCALER/POSTSCALER
The CLRWDT and PWRSAV instructions
clear the prescaler and postscaler counts
when executed.
WINDIS
WDT BLOCK DIAGRAM
WDT
) of 1 ms in 5-bit mode, or
(divide by N1)
WDTPRE
Prescaler
RS
WDT Window Select
Preliminary
Watchdog Timer
RS
21.4.2
If the WDT is enabled, it will continue to run during Sleep
or Idle modes. When the WDT time-out occurs, the
device will wake the device and code execution will
continue from where the PWRSAV instruction was
executed. The corresponding SLEEP or IDLE bits
(RCON<3> and RCON<2>, respectively) will need to be
cleared in software after the device wakes up.
21.4.3
The WDT is enabled or disabled by the FWDTEN
Configuration bit in the FWDT Configuration register.
When the FWDTEN Configuration bit is set, the WDT is
always enabled.
The WDT can be optionally controlled in software when
the FWDTEN Configuration bit has been programmed
to ‘0’. The WDT is enabled in software by setting the
SWDTEN control bit (RCON<5>). The SWDTEN con-
trol bit is cleared on any device Reset. The software
WDT option allows the user application to enable the
WDT for critical code segments and disable the WDT
during non-critical segments for maximum power
savings.
The WDT flag bit, WDTO (RCON<4>), is not automatically
cleared following a WDT time-out. To detect subsequent
WDT events, the flag must be cleared in software.
WDTPOST<3:0>
(divide by N2)
Note:
Postscaler
CLRWDT Instruction
SLEEP AND IDLE MODES
ENABLING WDT
If the WINDIS bit (FWDT<6>) is cleared, the
CLRWDT instruction should be executed by
the application software only during the last
1/4 of the WDT period. This CLRWDT win-
dow can be determined by using a timer. If
a CLRWDT instruction is executed before
this window, a WDT Reset occurs.
© 2009 Microchip Technology Inc.
Sleep/Idle
1
0
WDT
Wake-up
WDT
Reset