Datasheet
Mode Register MR6
Table 14. MR6 Definition
BG0
BA1
BA0
RAS#
/A16
CAS#
/A15
WE#/
A14
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
1
1
0
0
0
0
0
*1
t
CCD_L
0
*1
0
*1
V
REFDQ
Training
V
REFDQ
Range
V
REFDQ
Training Value
Note 1. Reserved for future use and must be programmed to 0 during MRS.
t
CCD_L
Programming
The device controller must program the correct tCCD_L value. tCCD_L will be programmed according to the
value defined per operating frequency in the AC parameter table.
V
REFDQ
Training Enable
V
REFDQ
Training is where the device internally generates its own V
REFDQ
to be used by the DQ input
receivers. The device controller is responsible for setting and calibrating the internal V
REFDQ
level using an
MRS protocol (adjust up, adjust down, etc.). The procedure is a series of Writes and Reads in conduction with
V
REFDQ
adjustments to optimize and verify the data eye. Enabling V
REFDQ
Training must be used whenever
values are being written to the MR6[6:0] register.
V
REFDQ
Training Range
The device defines two V
REFDQ
calibration ranges: Range 1 and Range 2. Range 1 supports V
REFDQ
between
60% and 92% of V
DDQ
while Range 2 supports V
REFDQ
between 45% and 77% of V
DDQ
, Range 1 was targeted
for module-based designs and Range 2 was added to target point to-point designs.
V
REFDQ
Training Value
Fifty settings provide approximately 0.65% of granularity steps sizes for both Range 1 and Range 2 of V
REFDQ
.
A12
A11
A10
t
CCD_L.min
(t
CK
)
t
DLLK.min
(t
CK
)
Note
A6
V
REFDQ
Range
0
0
0
4
597
Data rate
≦
1333Mbps
0
Range 1
0
0
1
5
597
1333Mbps < Data rate ≦1866Mbps
1
Range 2
0
1
0
6
768
1866Mbps < Data rate ≦2400Mbps
0
1
1
7
1024
2400Mbps
<
Data rate
≦
2666Mbps
A7
V
REFD
Training
1
0
0
Reserved
Reserved
Reserved
0
Disable
1
0
1
Reserved
-
Reserved
1
Enable
1
1
0
Reserved
-
Reserved
1
1
1
Reserved
-
Reserved
A5:A0
Range1
Range2
A5:A0
Range1
Range2
A5:A0
Range1
Range2
A5:A0
Range1
Range2
000000
60.00%
45.00%
001101
68.45%
53.45%
01 1010
76.90%
61.90%
10 0111
85.35%
70.35%
000001
60.65%
45.65%
001110
69.10%
54.10%
01 1011
77.55%
62.55%
10 1000
86.00%
71.00%
000010
61.30%
46.30%
001111
69.75%
54.75%
01 1100
78.20%
63.20%
10 1001
86.65%
71.65%
000011
61.95%
46.95%
010000
70.40%
55.40%
01 1101
78.85%
63.85%
10 1010
87.30%
72.30%
000100
62.60%
47.60%
010001
71.05%
56.05%
01 1110
79.50%
64.50%
10 1011
87.95%
72.95%
000101
63.25%
48.25%
010010
71.70%
56.70%
01 1111
80.15%
65.15%
10 1100
88.60%
73.60%
000110
63.90%
48.90%
010011
72.35%
57.35%
10 0000
80.80%
65.80%
10 1101
89.25%
74.25%
000111
64.55%
49.55%
010100
73.00%
58.00%
10 0001
81.45%
66.45%
10 1110
89.90%
74.90%
001000
65.20%
50.20%
010101
73.65%
58.65%
10 0010
82.10%
67.10%
10 1111
90.55%
75.55%
001001
65.85%
50.85%
010110
74.30%
59.30%
10 0011
82.75%
67.75%
11 0000
91.20%
76.20%
001010
66.50%
51.50%
010111
74.95%
59.95%
10 0100
83.40%
68.40%
11 0001
91.85%
76.85%
001011
67.15%
52.15%
011000
75.60%
60.60%
10 0101
84.05%
69.05%
11 0010
92.50%
77.50%
001100
67.80%
52.80%
011001
76.25%
61.25%
10 0110
84.70%
69.70%
11 0011 to 111111 : Reserved
AS4C256M16D4
Confidential
- 26 of 201 -
Rev.1.0 Aug.2019