在文档里面，写着这样的一段
The I2C bus uses two wires to transfer information between devices connected
to  the  bus:  “SCL”  (serial  clock  line)  and  “SDA”  (serial  data  line).  The  I2C
component  requires  the  use  of  external  open-drain  buffers  since  it  has  only
unidirectional  ports. The “SDA” and “SCL” lines referred further are the actual
I2C bus signals, while the I2C component is connected to them with the use of
open-drains  (“SDAO”  as  output  and  “SDAI”  as  input,  “SCLO”  as  output  and
“SCLI” as input). Each device connected to the bus is software addressable by a
unique address. The I2C is a true multi-master bus including collision detection
and arbitration to prevent data corruption if two or more masters simultaneously
initiate  data  transfer.  The  filtering  logic  rejects  spikes  on  the  bus  data  line  to
preserve data integrity.

请问各位，这两个IO是不是还要接什么东西么？我现在直接使用芯片的IO，操作没有I2C的信号出来。