Looking for available TIMn ETR pins on Portenta H7

Official Hardware Portenta Family Portenta H7
1

i've got this code that works great on TIM2 and PA0 but i just found a conflict with this pin when using the SDMMC card. can anyone help locate an available ETR pin that is somewhat accessible on and arduino PortentaH7 docked to a Portenta breakout board? i use document stm32h747ag.pdf starting on Page 89 Table 9. PortA alternate functions but am having trouble find a pin that doesn't get trampled on by some mbed code or i am assume that is what is doing the trampling.

here is my code and ISR

volatile uint32_t secondsCounter = 0;
volatile uint8_t topSec = 0;

void setupTIM2() {
  RCC->APB1LENR |= RCC_APB1LENR_TIM2EN;  // Enable TIM2 clock
  TIM2->CR1 = 0;                         // Reset control register
  TIM2->PSC = 4;                         // Prescaler set to 5 (PSC + 1)
  TIM2->ARR = 0xFFFFFFFF;                // Max auto-reload value (free-running)
  TIM2->CNT = 0;                         // Reset counter
  TIM2->DIER |= TIM_DIER_UIE;            // Enable update interrupt

  // Configure PA0 as Alternate Function (AF1 for TIM2_ETR)
  GPIOA->MODER &= ~(0b11 << (0 * 2));  // Clear mode bits
  GPIOA->MODER |= (0b10 << (0 * 2));   // Set to Alternate Function mode
  GPIOA->AFR[0] &= ~(0xF << (0 * 4));  // Clear AF selection
  GPIOA->AFR[0] |= (0x1 << (0 * 4));   // Set AF1 (TIM2_ETR)

  // Configure TIM2 to use external clock mode 1 on ETR (PA0)
  TIM2->SMCR = (7 << TIM_SMCR_SMS_Pos) |  // External Clock Mode 1
               (7 << TIM_SMCR_TS_Pos) |   // Trigger source = ETR (PA0)
               (1 << 12);                 // Set ETR prescaler to divide by 2

  // Ensure ETR is active high
  TIM2->SMCR &= ~(1 << 15);  // Clear ETP bit to select active high

  // Disable digital filtering on ETR
  //TIM2->SMCR &= ~(0b1111 << 8);  // Clear ETR filter bits

  TIM2->ARR = 999999;  // Set rollover to 1,000,000 counts
  TIM2->CR1 |= TIM_CR1_ARPE;

  //TIM2->EGR = TIM_EGR_UG;    // Manually trigger an update event
  TIM2->CR1 |= TIM_CR1_CEN;   // Enable the counter
  NVIC_EnableIRQ(TIM2_IRQn);  // Enable TIM2 interrupt in NVIC
}

extern "C" void TIM2_IRQHandler() {
  if (TIM2->SR & TIM_SR_UIF) {  // Check if update interrupt flag is set
    TIM2->SR &= ~TIM_SR_UIF;    // Clear the interrupt flag
    secondsCounter++;           // Increment seconds counter
    topSec = 1;
  }
}