PIC18LF4331-ESLASHML datasheet(192/392 Pages) MICROCHIP

192 / 392 page

PIC18F2331/2431/4331/4431

DS39616D-page 192

 2010 Microchip Technology Inc.

18.7.2

DEAD-TIME RANGES

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

been provided to allow a suitable range of dead times

based on the device operating frequency. FOSC/2,

FOSC/4, FOSC/8 and FOSC/16 are the clock prescaler

options available using the DTPS<1:0> 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

comparison edge event;

• On a write to the DTCON register; or

• On any device Reset.

18.7.3

DECREMENTING THE DEAD-TIME

COUNTER

The dead-time counter is clocked from any of the Q

clocks based on the following conditions.

The dead-time counter is clocked on Q1 when:

• The DTPS bits are set to any of the following

dead-time prescaler settings: FOSC/4,

FOSC/8, FOSC/16

• The PWM Time Base Prescale bits

(PTCKPS) are set to any of the following

prescale ratios: FOSC/16, FOSC/64, FOSC/256

The dead-time counter is clocked by a pair of Q

clocks when the PWM Time Base Prescale bits

are set to 1:1 (PTCKPS<1:0> = 00, FOSC/4) and

the dead-time counter is clocked by the FOSC/2

(DTPS<1:0> = 00).

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

Q3, then the dead-time counter is clocked

using every Q1 and Q3.

• If the PWM duty cycle match occurs on Q2 or

Q4, then the dead-time counter is clocked

using every Q2 and Q4.

When the DTPS<1:0> bits are set to any of the

other dead-time prescaler settings (i.e., FOSC/4,

FOSC/8 or FOSC/16) and the PWM time 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.

DTCON: DEAD-TIME CONTROL REGISTER

R/W-0

DTPS1

DTPS0

DT5

DT4

DT3

DT2

DT1

DT0

bit 7

bit 0

Legend:

R = Readable bit

W = Writable bit

U = Unimplemented bit, read as ‘0’

-n = Value at POR

‘1’ = Bit is set

‘0’ = Bit is cleared

x = Bit is unknown

bit 7-6

DTPS<1:0>:

Dead-Time Unit A Prescale Select bits

= Clock source for dead-time unit is FOSC/16

= Clock source for dead-time unit is FOSC/8

= Clock source for dead-time unit is FOSC/4

= Clock source for dead-time unit is FOSC/2

bit 5-0

DT<5:0>:

Unsigned 6-Bit Dead-Time Value for Dead-Time Unit bits

PIC18LF4331-E/ML Datasheet(PDF) 192 Page - Microchip Technology

PIC18LF4331-E/ML Datasheet(HTML) 192 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL