topic Re: usart clock in Other NXP Products

usart clock

syedhashmiraza — Sat, 30 Nov 2024 06:26:06 GMT

helllo iam using lpc55s69 board and in that iam taking two usart zero for rx tx and usart 1 for genrate clock for iso7816 protocol communication with smatcard in that i want to genatrate 705mhz clock in usart 1 how to genarate clock in usart 1?

Re: usart clock

xiangjun_rong — Mon, 02 Dec 2024 04:10:15 GMT

Hi,

I suppose that the uart of LPC55xx does not support iso7816 protocol, if you do want a chip which supports iso7816 protocol, I suggest you consider

MCXN family for example MCXN947, which has dedicated EMVSIM module

https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/general-purpose-mcus/mcx-arm-cortex-m/mcx-n-series-microcontrollers:MCX-N-SERIES

Hope it can help you

Xiangjun Rong

usart clock

syedhashmiraza — Mon, 02 Dec 2024 05:44:01 GMT

hello my question is how to genarate clock on usart for lpc5569

Re: usart clock

xiangjun_rong — Mon, 02 Dec 2024 07:10:11 GMT

Hi,

Regarding your question, the UART driving clock can not exceed 44Mhz.

For the FRG module, each FCx module has it's own FRGx module. The FRG has MULT and DIV parts, the DIV is fixed to be 0xFF or 256 in decimal.

The uart driving clock is from FRG, the FRG clock is

CLK/(1+MULT/DIV)=CLK*DIV/（MULT+DIV）

The CLK configuration tools has the GUI to set the FC module clock

The Multiply is fixed 256 in decimal, the DIV is from 256 to 511 in decimal

so you can configure the uart clock, but it can not exceed 44mhz.

If you set the FRGCTRLx_DIV as 436, the uart driving clock can be 44MHz.

Hope it can help you

XiangJun Rong

Re: usart clock

syedhashmiraza — Thu, 05 Dec 2024 05:38:42 GMT

HELLO I Tried this one but in usart not genrating clock , can you provide a code or more information?

Re: usart clock

xiangjun_rong — Fri, 06 Dec 2024 09:03:14 GMT

Hi,

Can you post you project and tell us the target so that we can support you

XiangJun Rong

Re: usart clock

syedhashmiraza — Fri, 06 Dec 2024 12:55:43 GMT

hello i want to genarate clock on usart 7.5mhz , and the clock generate continous , how i can genarte the usart clock?

#include "pin_mux.h"

#include "board.h"

#include "fsl_usart.h"

#include <stdbool.h>

#include "fsl_power.h"

/*******************************************************************************

* Definitions

******************************************************************************/

#define DEMO_USART USART0

#define DEMO_USART_CLK_SRC kCLOCK_Flexcomm1

#define DEMO_USART_CLK_FREQ CLOCK_GetFlexCommClkFreq(0U)

#define DEMO_USART_IRQHandler FLEXCOMM0_IRQHandler

#define DEMO_USART_IRQn FLEXCOMM0_IRQn

/*! @brief Ring buffer size (Unit: Byte). */

#define DEMO_RING_BUFFER_SIZE 16

/*******************************************************************************

* Prototypes

******************************************************************************/

#define CARD_CLK 6000000 ///< Target card clock rate.

#define CARD_CLK_DIV (SystemCoreClock / CARD_CLK) ///< Clock divisor from core clock to card clock.

#define DEFAULT_ETU 372

#define GPIO_PORT 1

#define GPIO_PIN 9

//#define IOCON_INDEX_PIO0_9

//#define IOCON_PIN_CARD_CLK IOCON_INDEX_PIO0_9

static uint16_t currentETU = DEFAULT_ETU;

/*******************************************************************************

* Variables

******************************************************************************/

uint8_t g_tipString[] =

"USART functional API interrupt example\r\nBoard receives characters then sends them out\r\nNow please input:\r\n";

uint8_t demoRingBuffer[DEMO_RING_BUFFER_SIZE];

volatile uint16_t txIndex;

volatile uint16_t rxIndex;

volatile uint16_t lastRxIndex; // Variable to store the last received index

/*******************************************************************************

* Code

******************************************************************************/

void ISO7816_SetClocks() {

CLOCK_EnableClock(kCLOCK_FlexComm0);

CLOCK_AttachClk(kMAIN_CLK_to_FLEXCOMM0);

CLOCK_EnableClock(kCLOCK_FlexComm1);

CLOCK_AttachClk(kMAIN_CLK_to_FLEXCOMM1);

}

int main(void)

{

CLOCK_SetupFROClocking(12000000U);

//CLOCK_SetMainClkSrc(kCLOCK_MainClkSrcFro);

CLOCK_GetMclkClkFreq();

SystemCoreClockUpdate();

usart_config_t config;

POWER_SetBodVbatLevel(kPOWER_BodVbatLevel1650mv, kPOWER_BodHystLevel50mv, false);

CLOCK_AttachClk(BOARD_DEBUG_UART_CLK_ATTACH);

BOARD_InitBootPins();

BOARD_BootClockFRO12M();

BOARD_InitDebugConsole();

CLOCK_EnableClock(kCLOCK_Iocon);

CLOCK_EnableClock(kCLOCK_Gpio0);

CLOCK_EnableClock(kCLOCK_Gpio1);

ISO7816_SetClocks();

ISO7816_Init();

// GPIO_PinWrite(GPIO, GPIO_PORT, GPIO_PIN, 1);

IOCON_PinMuxSet(IOCON,GPIO_PORT ,GPIO_PIN, IOCON_MODE_PULLDOWN);

USART_GetDefaultConfig(&config);

config.baudRate_Bps = BOARD_DEBUG_UART_BAUDRATE;

config.enableTx = true;

config.enableRx = true;

USART_Init(DEMO_USART, &config, DEMO_USART_CLK_FREQ);

}