manualshive.com logo in svg

Cypress FR81S CY91520 Series, Рекомендации по настройке оборудования

Поделиться
Скачать
Cypress FR81S CY91520 Series Скачать руководство пользователя страница 24

 

Recommendation for Hardware Setup 32-Bit FR81S Family 

www.cypress.com

 

Document No. 002-09375 Rev. *B 

24 

 

4.3 

5 V Tolerant Input pins 

In case of using of MCU on 3 V level and peripherals on 5 V level of power supply the ESD please note the influence 
of ESD clamping structure of usual GPIO pin. 

Figure 29. Standard IO and 5 V Tolerant IO 

VCC

+3V

+5V

VCC

VSS

VSS

IN

OUT

MCU

Peripheral

 

VCC

+3V

+5V

VCC

VSS

VSS

IN

OUT

MCU

Peripheral

5V tolerant

input

 

(a)  Standard IO 

 

 

 

 

(b) 5 V Tolerant IO 

 

For 5 V Tolerant IO, the diode is not attached to the Pch side. It is a protection circuit in the parasitic bipolar and the 
diode to VSS. For the reason, clamp current cannot be specified in  the DS for such kind of input pins. 5 V tolerant 
inputs  are  e.g.  for  CY91

F52x:  P035,  P041,  P093,  P122.  Please  see  also  the  note  *6  in  the  DS  “ELECTRICAL 

CHARACTERISTICS 

– Maximum clamp current”. The current limitation with series resistor for + B signal is input is not 

possible for a 5 V tolerant input. 

 

 

Содержание FR81S CY91520 Series

Страница 1: ...nded Power Supply Circuit 12 3 7 Reset circuit 13 3 8 Quartz Crystal Placement and Signal Routing 16 3 9 Test points 18 3 10 Other documents 18 4 Port Input Unused Pins Latch up 19 4 1 Port Input Unus...

Страница 2: ...ist The MAX232 is a standard level shifter which converts the 5 V levels of the MCU to 12V RS232V24 levels and vice versa If you use a 3 3 V system a MAX3232 is recommended Please consider that the in...

Страница 3: ...capacitor Cext approx 0 1 F to the analog input pin An input impedance maximum Rext 15k Ohm is recommended So an appropriate sample time has to be selected depending on the impedance Rext and the capa...

Страница 4: ...dance may cause latch up effects together with an RSTX Switch and low EMI protection The reset level of RSTX pins depends on the logical level on NMIX pin Please refer to Hardware manual chapter 7 Res...

Страница 5: ...GPIO GPIO OSC GPIO Vcc Vcc 5V Vcc Vss GND Vss GND 5V 5V 5V GND Vss GND Vcc Vss C Internal 1 2V Vss GND 4 7 F ceramic X7R CORE internal voltage regulator 1 Note 1 Vss pin closest to C pin 2 9 Clock So...

Страница 6: ...Handling devices for further information The following settings are used for the both modes mentioned above Table 3 Mode Pin Settings x does not care Mode P006 MD0 MD1 Serial Programming Mode 1 0 1 Ru...

Страница 7: ...k D1 e g HZM6 2Z4MFA E D2 schottky diode e g BAS40 Debug connector SMA 50R connector for development target boards Table 4 SPEED BOX General Specifications Item Specification MDI bus maximum communic...

Страница 8: ...have to be placed as near as possible to the X1 A pins output of the inverter The feedback resistor of oscillator circuit typ 1Mohm is already implemented internally The evaluation of crystal resonat...

Страница 9: ...ss of the whole circuit to avoid a ground loop Below is a principal example of a bad and a good power line routing Figure 5 Example of bad vs good power line routing For four and more layers PCB the V...

Страница 10: ...ls BAD crosstalk between different power supply planes GND Avcc Vcc low speed signals high speed signals GOOD separation of power supply planes for low EMC requirements 3 5 Power Supply Decoupling DeC...

Страница 11: ...oards is recommended Figure 8 Power Supply decoupling on single side assembled boards L4 L3 VCC L2 GND L1 MCU VCC VSS MCU CB The following routing and placement for multi layer PCB is recommended Note...

Страница 12: ...d IO pins like stepper motor controller or external bus interface can generate spikes on the supplies These are difficult to filter using capacitors only A series inductor ferrite e g WE742792022 is t...

Страница 13: ...ard reset extension circuit to guarantee the stabilization of the Low Voltage Detector LVD and complete reset of the device before program execution starts The reset signal at RSTX pin goes through a...

Страница 14: ...dware Setup 32 Bit FR81S Family www cypress com Document No 002 09375 Rev B 14 Please see also the datasheet chapter External reset timing of related MCU series Table 7 External reset timing Figure 12...

Страница 15: ...Recommendation for Hardware Setup 32 Bit FR81S Family www cypress com Document No 002 09375 Rev B 15 Figure 13 Block Diagram of reset extension circuit...

Страница 16: ...f MCU device The value of both load capacitors C1 C2 should be determined with crystal matching test The crystal matching test must be done by the crystal manufacturer based on the target board As a r...

Страница 17: ...pins Figure 16 Layout example for crystal oscillator circuit DeCap CB on backside Vias to Vcc plane on inner layers Vias to ground plane on inner layers Ground plane on inner layers X0 Vcc Vss CB SMD...

Страница 18: ...nctions for failure analysis in development mass production or in the field MONCLK out could be used e g for clock calibration of main or sub oscillator Figure 18 MONCLK internal clock select and pres...

Страница 19: ...define the input level If both solutions are not possible set the Port Pin to Output Never connect a potential divider with almost same resistor values Figure 19 Principle using of input circuit to a...

Страница 20: ...ground together with debouncing capacitors connected to port pins A usual configuration is shown in the following schematic Figure 20 Usual Configuration Switch RPD is a pull down resistor and CBD a d...

Страница 21: ...osing Point A But at the port pin Pxy on point B the following voltage can be measured Figure 23 Signal rise on switch closing Point B By closing the switch SW the circuit becomes a parallel oscillato...

Страница 22: ...on the port pin The frequency of the oscillation can be calculated by Equation Oscillation frequency DB X OSC C L f 2 1 The inductivity LX is the unknown value and depends on the PCB its routing and...

Страница 23: ...like in the following schematic Figure 27 Series resistor The series resistor RS reduces the amplitude of the oscillation and decreases the voltage offset at first The resistor must not be chosen too...

Страница 24: ...al VCC 3V 5V VCC VSS VSS IN OUT MCU Peripheral 5V tolerant input a Standard IO b 5 V Tolerant IO For 5 V Tolerant IO the diode is not attached to the Pch side It is a protection circuit in the parasit...

Страница 25: ...o achieve that nowadays you can do it in different ways using a regular serial cable if a DB9 serial connector is present in the computer or using a more modern USB cable i e FTDI TTL 232R http www ft...

Страница 26: ...stem as you can see in the Figure 31 using only one signal connected to pin MD0 inverting MD1 and a pull up resistor on the pin P006 Figure 31 Principal Schematic for serial programming via Usart0 Fla...

Страница 27: ...g is the MDI interface using only one signal pin Debug I F through the MB2100 01 E debugger The MB2100 01 E debugger is connected to the host computer with an USB cable and to the target PCB with a si...

Страница 28: ...B 28 Figure 34 Picture of the MB2100 01 E Figure 35 Electronic Components needed to protect the Debug I F pin VCC Debug Connector R1 ECU GND R2 D2 DEBUGIF MCU D1 GND R1 43 R R2 10 k D1 e g HZM6 2Z4MF...

Страница 29: ...e this function the user has to write in a specific flash memory location a password and a flash security code From then security is turned on and access restrictions are imposed on subsequent accesse...

Страница 30: ...ed HiZ If some external bus pins should be used as GPIO than do not use any address or bus control lines as input because these lines are driven as output high 7 Additional Information Information abo...

Страница 31: ...release RSTX and NMIX input section correction RSTX and NMIX input obsolete issue removed Added new section 5V tolerant IOs 01 06 2014 V1 3 FTo 02 11 2015 V1 4 FTo Modified Figure 1 Principle schemati...

Страница 32: ...ability arising out of any security breach such as unauthorized access to or use of a Cypress product CYPRESS DOES NOT REPRESENT WARRANT OR GUARANTEE THAT CYPRESS PRODUCTS OR SYSTEMS CREATED USING CYP...

Отзывы:

Нет отзывов

Бренды по названию

Популярные бренды

Загрузить еще бренды