PIC18F4431-E/PT Microchip Technology, PIC18F4431-E/PT Datasheet - Page 202

• Manufacturer Part Number: PIC18F4431-E/PT
• Description: IC MCU FLASH 8KX16 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4431-E/PT

• Core Size: 8-Bit
• Program Memory Size: 16KB (8K x 16)
• Oscillator Type: Internal
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, Power Control PWM, QEI, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 9x10b
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 44-TQFP, 44-VQFP
• Controller Family/series: PIC18
• No. Of I/o's: 36
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 768Byte
• Cpu Speed: 40MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIC18F2331/2431/4331/4431
REGISTER 17-5:
17.7.2
The amount of dead time provided by the dead time
unit is selected by specifying the input clock prescaler
value and a 6-bit unsigned value defined in the DTCON
register. Four input clock prescaler selections have
been provided to allow a suitable range of dead times
based on the device operating frequency. F
F
options available using the DTPS1:DTPS0 control bits
in the DTCON register.
After selecting an appropriate prescaler value, the
dead time is adjusted by loading a 6-bit unsigned value
into DTCON<5:0>. The dead time unit prescaler is
cleared on any of the following events:
• On a load of the down timer due to a duty cycle
• On a write to the DTCON register; or
• On any device Reset.
17.7.3
The dead time counter is clocked from any of the Q
clocks based on the following conditions.
1.
2.
DS39616B-page 200
OSC
comparison edge event;
The dead time counter is clocked on Q1 when:
• The DTPS bits are set to any of the following
• The PWM Time Base Prescale bits
The dead time counter is clocked by a pair of
Q-clocks when the PWM Time Base Prescale
bits are set to 1:1 (PTCKPS1:PTCKPS0 = 00,
F
the F
/4, F
OSC
dead time prescaler settings: Fosc/4, F
F
(PTCKPS) are set to any of the following
prescale ratios: F
F
OSC
OSC
OSC
/4) and the dead time counter is clocked by
OSC
DEAD TIME RANGES
DECREMENTING THE DEAD TIME
COUNTER
bit 7-6
bit 5-0
/16
/256.
/2 (DTPS1:DTPS0 = 00).
/8 and F
DTPS1:DTPS0: Dead Time Unit A Prescale Select bits
11 = Clock source for Dead Time Unit is F
10 = Clock source for Dead Time Unit is F
01 = Clock source for Dead Time Unit is F
00 = Clock source for Dead Time Unit is F
DT5:DT0: Unsigned 6-bit dead time value bits for Dead Time Unit.
Legend:
R = Readable bit
-n = Value at POR
bit 7
DTCON – DEAD TIME CONTROL REGISTER
OSC
DTPS1
R/W-0
OSC
/16 are the clock prescaler
/16, F
OSC
DTPS0
R/W-0
/64,
OSC
R/W-0
OSC
DT5
/8,
W = Writable bit
‘1’ = bit is set
Preliminary
/2,
R/W-0
DT4
OSC
OSC
OSC
OSC
3.
4.
The actual dead time is calculated from the DTCON
register as follows:
Dead Time = Dead time value / (F
Table 17-3 shows example dead time ranges as a
function of the input clock prescaler selected and the
device operating frequency.
/16.
/8.
/4.
/2.
The dead time counter is clocked using every
other Q-clock depending on the two LSbs in the
Duty Cycle registers:
• If the PWM duty cycle match occurs on Q1 or
• If the PWM duty cycles match occurs on Q2
When the DTPS1:DTPS0 bits are set to any of
the other dead time prescaler settings, (i.e.,
F
Base Prescaler is set to 1:1, the dead time
counter is clocked by the Q-clock corresponding
to the Q-clocks on which the PWM duty cycle
match occurs.
OSC
Q3, then the dead time counter is clocked
using every Q1 and Q3.
or Q4, then the dead time counter is clocked
using every Q2 and Q4.
R/W-0
U = Unimplemented bit, read as ‘0’
‘0’ = bit is cleared
DT3
/4, F
OSC
/8 or F
R/W-0
DT2
 2003 Microchip Technology Inc.
OSC
/16) and the PWM Time
x = bit is unknown
R/W-0
OSC
DT1
/prescaler)
R/W-0
DT0
bit 0