TTL（Time-to-Live）实际上是一个8比特的字段，在每个IP数据包的头部信息中都有这个字段。 TTL的主要作用是防止数据包在网络中无限制地传输或循环。

Point of terminology: "TTL serial" is a severely over-broad term, " (point-to-point) asynchronous serial (at TTL levels)" seems to be what you're asking about. (Though that's still probably lacking, but at least …

1. TTL电平 TTL指双极型三极管逻辑电路（transistor transistor logic），这种信号0对应0V，1对应3.3V或5V，与单片机、MCU、SOC的IO电平兼容。 不过实际也不一定是TTL电平，因为现在大部分数字逻 …

Jun 22, 2023 · TTL requires that logic 1 input must be at least 2V, and TTL drivers are designed to guarantee that. That is far short of what this driver requires to register as logic 1.

因为每经过一个路由器路由器会将ttl减1后发给下一跳，当ttl等于0路由器会丢弃该IP包。 所以ttl等于1时，路由器收到该包，减1，为0丢弃。

Aug 14, 2012 · TTL mean Transistor-Transistor-Logic and has its level for logical zero near 0V and for logical one near 5V. Often any 5V logic is called TTL, although most circuits nowadays are built as …

Feb 18, 2023 · I need to implement a TTL to RS485 converter into an home made project and searching by Google I found this module with related schematics: Could you help me by indicating the correct …

TTL是 递归DNS 缓存域名解析的时间，以秒为单位。 过期了递归DNS就会去找 权威DNS 重新查询。 （ 什么是TTL值？ ） 如果你的域名解析改动较频繁，比如使用 动态IP 等，就应该把TTL尽量设小； 如 …

Mar 21, 2018 · What is the difference of these two ttl nand gates? What is a totem pole, what does it do and what is it used for? When connecting multiple ttl logic gates together is it better to use one or the...

Feb 25, 2025 · Unsurprisingly, since we know that TTL pull-down needs to sink current from the input while a pull-up doesn't, the required TTL pull-down resistor value is smaller than the pull-up. How …