NEC VR4181 mPD30181 User Manual page 132

Bit Name
5, 4 Tcas(1:0)
3, 2 Trp(1:0)
1, 0 Tras(1:0)
This register is used to set EDO DRAM timing parameters. Software must set these parameters suitable before
using DRAM.
Remark Do not set Tcas = 1/2 TClock and Caspre = 1 TClock, or Tcas = 1 TClock and Caspre = 1/2 TClock at
the same time.
132
CHAPTER 6 BUS CONTROL
CAS pulse width
00 : 1/2 TClock
01 : 1 TClock
10 : 2 TClock
11 : Reserved
RAS precharge time
00 : 1 TClock
01 : 2 TClock
10 : 3 TClock
11 : 4 TClock
RAS pulse width
00 : 2 TClock
01 : 3 TClock
10 : 5 TClock
11 : 6 TClock
User's Manual U14272EJ3V0UM
Function
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