 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
HSP45116VC-25 Datasheet(PDF) 9 Page - Intersil Corporation |
|
||||||||||||||||||||||||||||||
HSP45116VC-25 Datasheet(HTML) 9 Page - Intersil Corporation |
|
|
9 / 18 page  9 Functional Description The Numerically Controlled Oscillator/Modulator (NCOM) produces a digital complex sinusoid waveform whose amplitude, phase and frequency are controlled by a set of input command words. When used as a Numerically Controlled Oscillator (NCO), it generates 16-bit sine and cosine vectors at a maximum sample rate of 33MHz. The NCOM can be preprogrammed to produce a constant (CW) sine and cosine output for Direct Digital Synthesis (DDS) applications. Alternatively, the phase and frequency inputs can be updated in real time to produce a FM, PSK, FSK, or MSK modulated waveform. The Complex Multiplier/ Accumulator (CMAC) can be used to multiply this waveform by an input signal for AM and QAM signals. By stepping the phase input, the output of the ROM becomes an FFT twiddle factor; when data is input to the Vector Inputs (see Block Diagram), the NCOM calculates an FFT butterfly. As shown in the Block Diagram, the NCOM consists of three parts: Phase and Frequency Control Section (PFCS), Sine/Cosine Generator, and CMAC. The PFCS stores the phase and frequency inputs and uses them to calculate the phase angle of a rotating complex vector. The Sine/Cosine Generator performs a lookup on this phase and outputs the appropriate values for the sine and cosine. The sine and cosine form one set of inputs to the CMAC, which multiplies them by the input vector to form the modulated output. Phase and Frequency Control Section The phase and frequency of the internally generated sine and cosine are controlled by the PFCS (Block Diagram). The PFCS generates a 32-bit word that represents the current phase of the sine and cosine waves being generated; the Sine/ Cosine Argument. Stepping this phase angle from 0 through full scale (232 - 1) corresponds to the phase angle of a sinusoid starting at 0o and advancing around the unit circle counterclockwise. The PFCS automatically increments the phase by a preprogrammed amount on every rising edge of the external clock. The value of the phase step (which is the sum of the Center and Offset Frequency Registers) is: The PFCS is divided into two sections: the Phase Accumulator uses the data on C0-15 to compute the phase angle that is the input to the Sine/Cosine Section (Sine/Cosine Argument); the Time Accumulator supplies a pulse to mark the passage of a preprogrammed period of time. The Phase Accumulator and Time Accumulator work on the same principle: a 32-bit word is added to the contents of a 32-bit accumulator register every clock cycle; when the sum causes the adder to overflow, the accumulation continues with the 32 bits of the adder going into the accumulator register. The overflow bit is used as an output to indicate the timing of the accumulation overflows. In the Time Accumulator, the overflow bit generates TICO, the Time Accumulator carry out (which is the only output of the Time Accumulator). In the Phase Accumulator, the overflow is inverted to generate the Phase Accumulator Carry Out, PACO. The output of the Phase Accumulator goes to the Phase Adder, which adds an offset to the top 16 bits of the phase. This 32-bit number forms the argument of the sine and cosine, which is passed to the Sine/Cosine Generator. Both accumulators are loaded 16 bits at a time over the C0-15 bus. Data on C0-15 is loaded into one of the three input registers when CS and WR are low. The data in the Most Significant Input Register and Least Significant Input Register forms a 32-bit word that is the input to the Center Frequency Register, Offset Frequency Register and Time Accumulator. These registers are loaded by enabling the proper register enable signal; for example, to load the Center Frequency Register, the data is loaded into the LS and MS Input Registers, and ENCFREG is set to zero; the next rising edge of CLK will pass the registered version of ENCFREG, R.ENCFREG, to the clock enable of the Center Frequency Register; this register then gets loaded on the following rising edge of CLK. The contents of the Input Registers will be continuously loaded into the Center Frequency Register as long as R.ENCFREG is low. The Phase Register is loaded in a similar manner. Assuming PMSEL is high, the contents of the Phase Input Register is loaded into the Phase Register on every rising clock edge that R.ENPHREG is low. If PMSEL is low, MOD0-1 supply the two most significant bits into the Phase Register (MOD1 is the MSB) and the least significant 14 bits are loaded with 0. MOD0-1 are used to generate a Quad Phase Shift Keying (QPSK) signal (Table 2). The Phase Accumulator consists of registers and adders that compute the value of the current phase at every clock. It has three inputs: Center Frequency, which corresponds to the carrier frequency of a signal; Offset Frequency, which is the deviation from the Center Frequency; and Phase, which is a 16-bit number that is added to the current phase for PSK Phase Step = Signal Frequency Clock Frequency ---------------------------------------------- 2 32 × TABLE 1. AD0-1 DECODING AD1 AD0 CS WR FUNCTION 000 ↑ Load least significant bits of frequency input. 010 ↑ Load most significant bits of frequency input. 100 ↑ Load phase register. 1 1 X X Reserved. X X 1 X No Operation. HSP45116 |
Similar Part No. - HSP45116VC-25 |
|
Similar Description - HSP45116VC-25 |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
