eMMC工作频率疑惑

njsssmq

THGBMNG5D1LBAIL 手册说明工作频率是52M。 CSD[103:96] TRAN_SPEED值是0x32.RL-FlashFS是通过下列代码获取最大传输频率是25M。THGBMNG5D1LBAIL CLK能配置为50M吗？
/**
  Determine maximum transfer speed from the CSD register data.
  \return maximum transfer speed in Hz
*/
static uint32_t get_tran_speed (uint32_t *r2) {
  static const uint8_t tim_val[] = {
    0, 10, 12, 13, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80
  };
  uint32_t i, n, m, speed;
  uint8_t *b;

  b = (uint8_t *)r2;

  /* Max. data transfer rate (TRAN_SPEED: CSD[103:96] */
  n = (b[12] >> 3) & 0xF;
  m = (b[12] & 0x7) + 1;
  speed = tim_val[n];
  for (i = 0; i < m; i++) {
    speed *= 10;
  }
  return (speed * 1000);
}

eric2013

按照早期的裸机方式下读43MB/S，写18.8MB/S，应该是50MHz下测试的。