EMIF
7.3.5.7
SDRAM_TIM_1 Register (offset = 18h) [reset = 0h]
SDRAM_TIM_1 is shown in
and described in
Figure 7-97. SDRAM_TIM_1 Register
31
30
29
28
27
26
25
24
Reserved
reg_t_rp
reg_t_rcd
R-0h
R/W-0h
R/W-0h
23
22
21
20
19
18
17
16
reg_t_rcd
reg_t_wr
reg_t_ras
R/W-0h
R/W-0h
R/W-0h
15
14
13
12
11
10
9
8
reg_t_ras
reg_t_rc
R/W-0h
R/W-0h
7
6
5
4
3
2
1
0
reg_t_rc
reg_t_rrd
reg_t_wtr
R/W-0h
R/W-0h
R/W-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 7-117. SDRAM_TIM_1 Register Field Descriptions
Bit
Field
Type
Reset
Description
31-29
Reserved
R
0h
28-25
reg_t_rp
R/W
0h
Minimum number of DDR clock cycles from Precharge to Activate or
Refresh, minus one.
24-21
reg_t_rcd
R/W
0h
Minimum number of DDR clock cycles from Activate to Read or
Write, minus one.
20-17
reg_t_wr
R/W
0h
Minimum number of DDR clock cycles from last Write transfer to
Pre-charge, minus one.
The SDRAM initialization sequence will be started when the value of
this field is changed from the previous value and the EMIF is in
DDR2 mode.
16-12
reg_t_ras
R/W
0h
Minimum number of DDR clock cycles from Activate to Pre-charge,
minus one.
reg_t_ras >= reg_t_rcd.
11-6
reg_t_rc
R/W
0h
Minimum number of DDR clock cycles from Activate to Activate,
minus one.
5-3
reg_t_rrd
R/W
0h
Minimum number of DDR clock cycles from Activate to Activate for a
different bank, minus one.
For an 8-bank DDR2 and DDR3, this field must be equal to
((tFAW/(4*tCK))-1).
2-0
reg_t_wtr
R/W
0h
Minimum number of DDR clock cycles from last Write to Read,
minus one.
431
SPRUH73H – October 2011 – Revised April 2013
Memory Subsystem
Copyright © 2011–2013, Texas Instruments Incorporated