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The following document contains information on Cypress products. The document has the series 
name, product name, and ordering part numbering with the prefix “MB”. However, Cypress will 
offer  these  products  to  new  and  existing  customers  with  the  series  name,  product  name,  and 
ordering part number with the prefix “CY”. 
 

How to Check the Ordering Part Number 

1.  Go to  

www.cypress.com/pcn

. 

2.  Enter the keyword (for example, ordering part number) in the 

SEARCH PCNS

 field and click 

Apply

3.  Click the corresponding title from the search results. 
4.  Download the Affected Parts List file, which has details of all changes 
 

For More Information 

Please  contact  your  local  sales  office  for  additional  information  about  Cypress  products  and 
solutions. 
 

About Cypress 

Cypress is the leader in advanced embedded system solutions for the world's most innovative 
automotive,  industrial,  smart  home  appliances,  consumer  electronics  and  medical  products. 
Cypress' microcontrollers, analog ICs, wireless and USB-based connectivity solutions and reliable, 
high-performance memories help engineers design differentiated products and get them to market 
first.  Cypress  is  committed  to  providing  customers  with  the  best  support  and  development 
resources on the planet enabling them to disrupt markets by creating new product categories in 
record time. To learn more, go t

www.cypress.com

. 

 

Содержание AN204772

Страница 1: ...ich has details of all changes For More Information Please contact your local sales office for additional information about Cypress products and solutions About Cypress Cypress is the leader in advanced embedded system solutions for the world s most innovative automotive industrial smart home appliances consumer electronics and medical products Cypress microcontrollers analog ICs wireless and USB ...

Страница 2: ...ply Decoupling 6 3 5 Quartz Crystal Placement and Signal Routing 8 3 6 Other documents 8 3 7 MCU Pin Summary 9 4 Port Input Unused Pins Latch up 10 4 1 Port Input Unused Pins 10 4 2 Latch up consideration switch 11 5 Minimum Flash Programming Connection 14 5 1 Run mode and Programming Mode 14 5 2 Programming Pins 14 5 3 Asynchronous Programming 15 5 4 Synchronous Programming 15 5 5 External Watchd...

Страница 3: ... If you use a 3 3V system a MAX3232 is recommended Please consider that the internal charge pumps of the level shifter can produce noise on the 5 Volts line which can influence the ADC if AVcc and AVRH are directly unfiltered connected to it If the system is set to Background Debugging Mode BDM the used DBM USART SIN pin shall be terminated to VCC Please see chapter 6 for details 2 3 Power supply ...

Страница 4: ...or will be damaged in worst case Also see chapter 3 2 8 Clock Source A clock source must be provided to the MCU Therefore crystals or external clock signals can be used For external source pin X0 X0A is used whereby pin X1 X1A is not connected The sub clock X0A pin has to be pulled down if sub clock is not used Please also refer to the chapter Outline Precautions for Device Handling in the corresp...

Страница 5: ...nd plane on the mounting side just under the MCU For both Vcc and Vss only one connection to the rest of the circuit should be done otherwise noise is carried over from and to the MCU Decoupling capacitors DeCaps has to be placed as nearest as possible to the related pins If they are placed too far away their function becomes useless If crystals are used they have to be placed as nearest as possib...

Страница 6: ...ingle sided metal layer is recommended Note that in all following illustrations the mounting metal layer is drawn in black and the back side metal layer in gray The following routing and placement for double sided metal layer is recommended Note that despite the capacitors are placed on the opposite side as the MCU this solution is the best ...

Страница 7: ...me inoperable The following graphic illustrates this For EMI reasons all decoupling capacitors should have the same capacitance so that all have a common resonance frequency Cypress recommends 10nF 100 MHz resonance to 100nF 10 MHz resonance depending on application For further detailed information please refer to the application note 16bit EMC Guideline The following routing and placement for sin...

Страница 8: ...ollowing routing and placement for double sided metal layer is recommended Note that despite the capacitor is placed on the opposite side as the MCU this solution is the best like for the C pin If mounting on both sides is not possible the following placement and routing is recommended ...

Страница 9: ...t as possible to the MCU Therefore the oscillator capacitors have to be placed behind the crystal For single metal layer circuit board the following placement and signal routing is recommended For double sided metal layer layout the following is recommended 3 6 Other documents For further detailed information please refer to the application note 16bit EMC Guideline ...

Страница 10: ...ads the most of noise Please refer to the DS of used MCU series for selection of capacitance value AVCC Power supply for the A D converter AVSS Power supply for the A D converter AVRL Reference voltage input for the A D converter AVRH Reference voltage input for the A D converter DVCC HVCC Power supply for the PWM high current outputs it is not connected to VCC should be connected to extra power s...

Страница 11: ...ut level The recommended way is to set the port input enable to 0 if a port pin is unconnected Never connect a potential divider with almost same resistor values Be careful with connection of input pins to other devices which can go into High Z states Always use internal pull up or external pull up or pull down resistors in this case Outputs from external circuits should always be connected via a ...

Страница 12: ...he switch SW is open a 0 is read from the port pin Pxy If the switch is closed the input changes to 1 From the physical aspect it has to be considered that the switch is often placed in distance to the MCU by cable wire or circuit path The longer the circuit path is the higher will be its inductivity LX and capacity CX An equivalent circuit diagram looks like the following illustration By closing ...

Страница 13: ...ply to be ideal i e it has no internal resistance Because RPD is often chosen high 50 K Ohms its damping effect is weak This weakly attenuated oscillator causes voltage overshoots on the port pin drawn in red in the illustration below These overshoots may cause an internal latch up on the port pin because the internal clamping diode connected to VCC becomes conductive Similar is the effect if the ...

Страница 14: ... measurements to prevent from latch up One solution is to decrease the capacity of the debouncing capacitor This increases the oscillation frequency and the over all energy of the overshoots is smaller big capacity small capacity This solution has two disadvantages First the debouncing effect decreases and second there is no guarantee that the latch up condition is eliminated A better solution is ...

Страница 15: ...ide then certain voltage levels for the mode pins and port pins Additionally it is possible to enable USART scanning in run mode by setting the magic word at address 0xDF0034 In this case the mode pins do not needed to be changed for programming and run mode Programming is possible after Reset If no communication is present after Reset the application is started 5 2 Programming Pins For serial pro...

Страница 16: ...e lines are short If ESD pulses are to expect two 2k pull up and down resistors have to be used as shown in the schematic above When the programmer is connected MD0 is connected to ground This configuration with MD1 1 and MD2 0 the MCU is in serial programming mode then If USART scanning is enabled the programmer connection to MD0 can be removed 5 4 Synchronous Programming The following schematic ...

Страница 17: ...ogramming mode In this case the capacitor will not discharge and the watchdog itself will not perform a reset The following schematic shows a possible solution 1 please see chapter 6 for details Assume the power of the MCUs circuits is off Then the programmer is connected and the power is switched on the reset phase begins The high level from the Vcc2 connector of the programmer is used via a diod...

Страница 18: ...Run Mode Note that in this case the watch dog is not retriggered so that the first watchdog reset occurs about 49 ms after the first power on reset 5 5 2 Timing Diagram of Programming Mode Note The capacitor on the D pin now is completely charged to 5 Volts so that the power on reset time becomes shorter ...

Страница 19: ...efore it is strongly recommended to terminate the SIN pin of this USART to VCC to avoid unwanted floating states at this input disturbing the debugging mode The user application if configured to auto run may not start or may stop during run time when the SIN pin is left unterminated and unconnected Termination to system ground is not recommended because the USART may interpret this as a start bit ...

Страница 20: ...mission Date Description of Change MKEA 08 17 2006 Initial Release 02 20 2007 Latch up diagram corrected 02 22 2007 C pin with single ceramic capacitor X7R 04 18 2007 Couple capacitors changed from 100nF to 10nF 06 11 2007 BDM USART recommendations added A 5060523 MKEA 12 22 2015 Migrated Spansion Application Note from MCU AN 300223 E V14 to Cypress format B 5834990 AESATMP8 07 27 2017 Updated log...

Страница 21: ... that are infringed by the Software as provided by Cypress unmodified to make use distribute and import the Software solely for use with Cypress hardware products Any other use reproduction modification translation or compilation of the Software is prohibited TO THE EXTENT PERMITTED BY APPLICABLE LAW CYPRESS MAKES NO WARRANTY OF ANY KIND EXPRESS OR IMPLIED WITH REGARD TO THIS DOCUMENT OR ANY SOFTW...

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