CHAPTER 6 BUS CONTROL
User’s Manual U14272EJ3V0UM
135
6.5.3 MODE_REG (0x0A00 0308)
Bit
15
14
13
12
11
10
9
8
Name
Reserved
Reserved
Reserved
Reserved
0
0
BR-SW
TE-Ven1
R/W
R
R
R
R
R/W
R/W
R/W
R/W
At reset
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
Name
TE-Ven2
LTMode2
LTMode1
LTMode0
WT
BL2
BL1
BL0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
At reset
0
0
0
0
0
0
0
0
Bit
Name
Function
15 to 12
Reserved
0 is returned when read
11, 10
0
These bits should be always written to 00.
9
BR-SW
Burst read - single write
This bit should be always written to 0.
8, 7
TE-Ven(1:2)
These two bits define a JEDEC test cycle and vendor specific cycles.
These bits should be always written to 00.
6 to 4
LTMode(2:0)
CAS latency mode
Note
010 : 2 clocks
011 : 3 clocks
Others : Reserved
3
WT
Wrap type for the burst cycles. This bit should be always written to 0.
0 : Sequential (default)
2 to 0
BL(2:0)
Burst length. These bits should be always written to 111.
111 : Full page (When WT = 0 only. Setting prohibited when WT = 1)
Note The CAS latency mode must be set according to the operation frequency of the SDCLK (SDRAM clock).
This register is used to set the value output to ADD(13:0) pins during the SDRAM mode register setting cycle. This
register should be written before the Init bit of MEMCFG_REG register is set to 1.
Содержание VR4181 mPD30181
Страница 2: ...User s Manual U14272EJ3V0UM 2 MEMO ...