chr_tout: timeout of the interval between each pattern characters, 24bit value, unit is APB (80Mhz) clock cycle. When the duration is less than this value, it will not take this data as at_cmd char
post_idle: idle time after the last pattern character, 24bit value, unit is APB (80Mhz) clock cycle. When the duration is less than this value, it will not take the previous data as the last at_cmd char
pre_idle: idle time before the first pattern character, 24bit value, unit is APB (80Mhz) clock cycle. When the duration is less than this value, it will not take this data as the first at_cmd char