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K4R881869M Datasheet, PDF (38/64 Pages) Samsung semiconductor – 288Mbit RDRAM 512K x 18 bit x 2*16 Dependent Banks Direct RDRAMTM | |||
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K4R881869M
Preliminary
Direct RDRAMâ¢
Control Register: TPARM
Address: 04816
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 0 0 0TCD0LY00 TCLS TCAS
Read/write register.
Reset value is undefined.
TCAS1..0 - Specifies the tCAS-C core parameter in
tCYCLE units. This should be â10â (2â¢t CYCLE).
TCLS1..0 - Specifies the tCLS-C core parameter in
tCYCLE units. Should be â10â (2â¢t CYCLE).
TCDLY0 - Specifies the tCDLY0-C core parameter in
tCYCLE units. This adds a programmable delay to Q
(read data) packets, permitting round trip read delay to
all devices to be equalized. This field may be written
with the values â011â (3â¢tCYCLE) through â101â
(5â¢t CYCLE).
.
The equations relating the core parameters to the
datasheet parameters follow:
tCAS-C = 2â¢t CYCLE
tCLS-C = 2â¢t CYCLE
tCPS-C = 1â¢t CYCLE
Not programmable
tOFFP = tCPS-C + tCAS-C + tCLS-C - 1â¢t CYCLE
= 4â¢tCYCLE
tRCD = tRCD-C + 1â¢t CYCLE - tCLS-C
= tRCD-C - 1â¢t CYCLE
tCAC = 3â¢t CYCLE + tCLS-C + tCDLY0-C + tCDLY1-C
(see table below for programming ranges)
TCDLY0 tCDLY0-C TCDLY1 tCDLY1-C
011
3â¢t CYCLE
000
0â¢tCYCLE
011
3â¢t CYCLE
001
1â¢tCYCLE
011
3â¢t CYCLE
010
2â¢tCYCLE
100
4â¢t CYCLE
010
2â¢tCYCLE
101
5â¢t CYCLE
010
2â¢tCYCLE
tCAC
8â¢tCYCLE
9â¢tCYCLE
10â¢tCYCLE
11â¢tCYCLE
12â¢tCYCLE
Figure 39: TPARM Register
Control Register: TFRM
Address: 04916
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
000000000000
TFRM3..0
Read/write register.
Reset value is undefined.
TFRM3..0 - Specifies the position of the framing point
in tCYCLE units. This value must be greater than or
equal to the tFRM,MIN parameter. This is the minimum
offset between a ROW packet (which places a device
at ATTN) and the first COL packet (directed to that
device) which must be framed. This field may be
written with the values â0111â (7â¢t CYCLE) through
â1010â (10â¢t CYCLE). TFRM is usually set to the value
which matches the largest tRCD,MIN parameter (modulo
4â¢t CYCLE) that is present in an RDRAM in the memory
system. Thus, if an RDRAM with tRCD,MIN = 9â¢tCYCLE
were present, then TFRM would be programmed to
5â¢tCYCLE.
Figure 40: TFRM Register
Control Register: TCDLY1
Address: 04a16
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0TCDLY1
Read/write register.
Reset value is undefined.
TCDLY1 - Specifies the value of the tCDLY1-C core
parameter in tCYCLE units. This adds a programmable
delay to Q (read data) packets, permitting round trip
read delay to all devices to be equalized. This field may
be written with the values â000â (0â¢t CYCLE) through
â010â (2â¢t CYCLE). Refer to Figure 39 for more details.
Figure 41: TRDLY Register
Page 36
Rev. 0.9 Jan. 2000
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