EMIF
7.3.5.11 SDRAM_TIM_3 Register (offset = 28h) [reset = 0h]
SDRAM_TIM_3 is shown in
and described in
.
Figure 7-101. SDRAM_TIM_3 Register
31
30
29
28
27
26
25
24
reg_t_pdll_ul
Reserved
R/W-0h
R-0h
23
22
21
20
19
18
17
16
Reserved
reg_zq_zqcs
R/W-0h
R/W-0h
15
14
13
12
11
10
9
8
reg_zq_zqcs
Reserved
reg_t_rfc
R/W-0h
R/W-0h
R/W-0h
7
6
5
4
3
2
1
0
reg_t_rfc
reg_t_ras_max
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 7-121. SDRAM_TIM_3 Register Field Descriptions
Bit
Field
Type
Reset
Description
31-28
reg_t_pdll_ul
R/W
0h
Minimum number of DDR clock cycles for PHY DLL to unlock.
A value of N will be equal to N x 128 clocks.
27-24
Reserved
R
0h
23-21
Reserved
R/W
0h
Reserved.
20-15
reg_zq_zqcs
R/W
0h
Number of DDR clock clock cycles for a ZQCS command, minus
one.
14-13
Reserved
R/W
0h
Reserved.
12-4
reg_t_rfc
R/W
0h
Minimum number of DDR clock cycles from Refresh or Load Mode to
Refresh or Activate, minus one.
3-0
reg_t_ras_max
R/W
0h
Maximum number of reg_refresh_rate intervals from Activate to
Precharge command.
This field must be equal to ((tRASmax / tREFI)-1) rounded down to
the next lower integer.
This field is only applicable for mDDR.
This field must be programmed to 0xF for other SDRAM types.
435
SPRUH73H – October 2011 – Revised April 2013
Memory Subsystem
Copyright © 2011–2013, Texas Instruments Incorporated