The following image is from the datasheet of SRAM IS64WV51216BLL(page 15).
It is a SRAM's write timing diagram.I don't know the meaning of double transitions for WE
signal.I have circled it in red.
Acturally I have searched many material,but nothing I wanted.Please help me!Thank you very much.
That is not multiple transitions, rather it is a timing window where the transition can happen which is bounded by two timing constraints: tSA and tPWE.
tSA is the Address Setup time which is the earliest that W̄ can be asserted. tPWE is the latest W̄ can be asserted and not violate the Pulse Width.