HT48R063 datasheet(46/94 Pages) HOLTEK

46 / 94 page

HT48R063/064/065/066/0662/067

Rev. 1.30

June 11, 2010

plimentary pair PFD and PFD for those devices with

dual outputs.

The Timer/Event Counter overflow signal is the clock

source for the PFD function, which is controlled by

PFDCS bit in CTRL0. For applicable devices the clock

source can come from either Timer/Event Counter 0 or

Timer/Event Counter 1. The output frequency is con-

trolled by loading the required values into the timer

prescaler and timer registers to give the required divi-

sion ratio. The counter will begin to count-up from this

preload register value until full, at which point an over-

flow signal is generated, causing both the PFD and PFD

outputs to change state. The counter will then be auto-

matically reloaded with the preload register value and

continue counting-up.

If the CTRL0 register has selected the PFD function,

then for both PFD outputs to operate, it is essential for

the Port A control register PAC, to setup the PFD pins as

outputs. If only one pin is setup as an output, the other

pin can still be used as a normal data input pin. How-

ever, if both pins are setup as inputs then the PFD will

not function. For devices with dual outputs the PFD out-

puts will only be activated if bit PA0 is set high. For de-

vices with a single PFD output, bit PA1 must be set high

to activate the PFD. These output data bits can be used

as the on/off control bit for the PFD outputs. Note that

the PFD outputs will all be low if the output data bit is

cleared to zero.

Using this method of frequency generation, and if a

crystal oscillator is used for the system clock, very pre-

cise values of frequency can be generated.

T i m e r O v e r f l o w

P F D C l o c k

P A 1 D a t a

P F D O u t p u t a t P A 1

PFD Function

· HT48R0662/HT48R067

T i m e r O v e r f l o w

P F D C l o c k

P A 0 D a t a

P F D O u t p u t a t P A 0

PFD Function - Single Output

T i m e r O v e r f l o w

P F D C l o c k

P A 0 o r P A 1 D a t a

P F D O u t p u t a t P A 0

P F D O u t p u t a t P A 1

PFD Function - Complementary Outputs

· HT48R063/HT48R064/HT48R065/HT48R066

HT48R063 Datasheet(PDF) 46 Page - Holtek Semiconductor Inc

HT48R063 Datasheet(HTML) 46 Page - Holtek Semiconductor Inc

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

Datasheet Download

Link URL