After the project code is compiled, the following information is printed:
Info: Clock “CLK48M†has Internal fmax of 67.47 MHz between source register “GLUE_LGC:glue|MCLK†and desTInaTIon register “img_lgc:img|N2DSP†(period= 14.822 ns)
The signal from MCLK to N2DSP defines the maximum speed of the hour hand to only 67.47MHz.
See the following code snippet in the relevant code:
Always @( posedge CLK48M )
Begin
CLKDIV <<= CLKDIV + 1; //clock divider
End
Always @(posedge CLKDIV[5])
Begin
MCLKB3 <<= MCLK_EXT;
MCLKB2 <<= MCLKB3;
MCLKB <<= MCLKB2;
MCLK <<= MCLKB | MCLKB2 | MCLKB3;
End
This code segment is a simple anti-shake process for MCLK_EXT, which is equivalent to using a clock CLKDIV[5] derived from CLK48M.
MCLK is latched again in other modules using the CLK48M system clock, so it is equivalent to complete the conversion of CLKDIV[5] between the two CLK48M clocks, and then use the rising edge of CLKDIV[5] to trigger the conversion of MCLK. Then output to the destination register. This process takes a long time, and the time spent by CLKDIV[5] is obviously redundant.
Modify the code as follows:
Always @( posedge CLK48M )
Begin
CLKDIV <<= CLKDIV + 1; //clock divider
If (CLKDIV == 6'b100000)
Begin
MCLKB3 <<= MCLK_EXT;
MCLKB2 <<= MCLKB3;
MCLKB <<= MCLKB2;
MCLK <<= MCLKB | MCLKB2 | MCLKB3;
End
End
The two logic functions are the same, but since the CLK48M clock is used only after the modification, the logic uses CLK48M as the trigger clock, which saves the delay of the first-level flip-flop, thus greatly shortening the source-to-destination register. Delay. Increased maximum clock rate. The maximum frequency information of the CLK48M system clock after compilation is as follows:
Info: Clock “CLK48M†has Internal fmax of 77.08 MHz between source register “img_lgc:img|DATABUF[13]†and desTInaTIon register “img_lgc:img|CAM_D[6]†(period= 12.974 ns)
It can be seen that the maximum frequency of CLK48M can reach 77.08M, which is determined by the path between "img_lgc:img|DATABUF[13]" to "img_lgc:img|CAM_D[6]". Continue to optimize for this network later.
This method of using derived clocks is a mistake in many people's logic design (because it has a very serious impact on timing, so it is not an error here), because it is typical, so it is specially organized, hope Attracted the attention of the primary logic engineer.
Yuhai piezo materials include : hard piezo material, soft piezo material and lead free piezo material
Soft piezo material exhibits: larger piezoelectric constants, higher permittivity, larger dielectric constants, higher dielectric losses, larger electromechanical coupling factors, low mechanical quality factors, a lower coercive field, poor linearity, and is easier to depolarize. The ideal application of soft piezo materials is sensing needs. Yuhai soft pizeo materials are PZT-5, PZT-5H, PSnN-5 and PLiS-51.
Hard piezo material exhibits: smaller piezoelectric constants, lower permittivity, smaller dielectric constants, lower dielectric losses, smaller electromechanical coupling factors, high mechanical quality factors, a higher coercive field, better linearity, and is harder to depolarize. The ideal application of hard piezo materials is high power transducer needs. Yuhai hard pizeo materials are PZT-4, PZT-8, PCrN-4 and PBaS-4.
Yuhai company developped lead free piezo material BaTiO3 and apply for the Chinese Patent in 2011, to meet the needs of environmental protection in today's society.
Piezoelectric ceramic material
Properties and Classification
General description of material properties
Material Code
Properties
Application
Soft PZT ceramic
PZT-51
Characteristics:
larger piezoelectric constants, higher permittivity, larger dielectric
constants, higher dielectric losses, larger electromechanical coupling
factors, low mechanical quality factors, a lower coercive field, poor
linearity, and is easier to depolarize.
low-power ultrasonic transducers
PZT-52
low-frequency sound transducers
PZT-53
applications with high g coefficient, for example,
PZT-5H
microphones,vibration pickups with preamplifier
PLiS-51
low-frequency vibration measurements
PMgN-51
Hydrophones, transducers in medical diagnostics
PSnN-5
Actuators
Hard PZT ceramic
PZT-41
Characteristics: smaller
piezoelectric constants, lower permittivity, smaller dielectric
constants, lower dielectric losses, smaller electromechanical coupling
factors, high mechanical quality factors, a higher coercive field,
better linearity, and is harder to depolarize.
PZT-42
High-power acoustic applications
PZT-43
Hydroacoustics, sonar technology
PZT-82
piezomotor
PCrN-4
PBaS-4
Lead free piezo ceramic
BaTiO3
Characteristics: Low density, low curie temperature, lead free.
Ultrasonic transducers suitable for low-temperature underwater, for example ultrasonic transducer in fishfinder
Piezoelectric Material,Piezo Ceramic Element,Piezo Electric Cylinder ,Piezo Sphere
Zibo Yuhai Electronic Ceramic Co., Ltd. , https://www.yhpiezo.com