random read
A random read operation requires a “dummy” write operation to load in the
target byte address Figure 28. This is accomplished by the following sequence:
The target 8-bit data word address is sent following the device address write
word (10100000 or 10100010) and acknowledged by the SFP+. The host then
generates another START condition (aborting the dummy write without incrementing
the counter) and a current address read by sending a device read address
(10100001 or 10100011). The SFP+ acknowledges the device address
and serially clocks out the requested data word. The host does not respond
with an acknowledge, but does generate a STOP condition once the data word
is read.
我英文不太好，我觉得还是直接看图，不过英文好的可以看看
HOST 代表主机
SFP+ 代表从机
主机首先发送开始信号，紧接着发送从机地址并告诉进行写操作，从机进行应答。
主机在发送存储地址，从机进行应答。
主机接着发送从机地址，此次进行写操作，从机应答
最后开始发送信号位，直至结束主机发送NACK，最后发送STOP信号。
sequential read
Sequential reads are initiated by either a current word address read Figure 29
or a random address read Figure 30. To specify a sequential read, the host responds
with an acknowledge (instead of a STOP) after each data word. As long
as the SFP+ receives an acknowledge, it shall serially clock out sequential data
words. The sequence is terminated when the host responds with a NACK and
a STOP instead of an acknowledge.
主机发送开始信号，接着发送从机地址，并发送读信号，本次直接进行读操作，从机应答
接着从机开始发送数据位，完成8bit后主机应答，接着从机继续发送8bit数据位，主机应答，直至发送结束，主机产生NACK后 ，主机接着发送STOP信号结束本次读操作。
看了英文就应该知道还有个是从随机读取开始，其实道理是一样的，只会起始条件改变，可以看看底下这幅图
这两幅图可以很形象的说明不同