W632GU8KB Datasheet, PDF (75/160 Pages) Winbond – 32M X 8 BANKS X 8 BIT DDR3L SDRAM

W632GU8KB
8.17.2 Power-Down clarifications - Case 1
When CKE is registered low for power-down entry, tPD(min) must be satisfied before CKE can be
registered high for power-down exit. The minimum value of parameter tPD(min) is equal to the
minimum value of parameter tCKE(min) as shown in section 10.16 “AC Characteristics” on page 137.
A detailed example of Case 1 is shown in Figure 69.
T0
T1
T2
Ta0
Ta1
Tb0
Tb1
Tb2
CK#
CK
Command
CKE
VALID
NOP
tIS
NOP
tPD
NOP
tIH
NOP
NOP
tIS
VALID
Address
tIH
VALID
tCPDED
tIS
tCKE
tCPDED
Enter
Power-Down
Mode
Exit
Power-Down
Mode
Enter
Power-Down
Mode
TIME BREAK
DON'T CARE
Figure 69 – Power-Down Entry/Exit Clarifications - Case 1
8.17.3 Power-Down clarifications - Case 2
For certain CKE intensive operations, for example, repeated ‘PD Exit - Refresh - PD Entry’ sequences,
the number of clock cycles between PD Exit and PD Entry may be insufficient to keep the DLL
updated. Therefore, the following conditions must be met in addition to tCKE in order to maintain
proper DRAM operation when the Refresh command is issued between PD Exit and PD Entry. Power-
down mode can be used in conjunction with the Refresh command if the following conditions are met:
1) tXP must be satisfied before issuing the command.
2) tXPDLL must be satisfied (referenced to the registration of PD Exit) before the next power-down can
be entered. A detailed example of Case 2 is shown in Figure 70.
T0
T1
T2
Ta0
Ta1
Tb0
Tb1
Tc0
Tc1
Td0
CK#
CK
Command
CKE
Address
VALID
NOP
NOP
tPD
tIS
NOP
tIH
NOP
NOP
REF
NOP
NOP
tIH
tIS
tCKE
VALID
tCPDED
Enter
Power-Down
Mode
Exit
Power-Down
Mode
tXP
tXPDLL
TIME BREAK
Figure 70 – Power-Down Entry/Exit Clarifications - Case 2
Enter
Power-Down
Mode
DON'T CARE
- 75 -
Publication Release Date: Jan. 20, 2015
Revision: A05