K4S56323LF Datasheet, PDF (11/12 Pages) Samsung semiconductor – 2M x 32Bit x 4 Banks Mobile SDRAM in 90FBGA

K4S56323LF - F(H)E/N/S/C/L/R
Mobile-SDRAM
Partial Array Self Refresh
1. In order to save power consumption, Mobile SDRAM has PASR option.
2. Mobile SDRAM supports 3 kinds of PASR in self refresh mode : Full Array, 1/2 of Full Array and 1/4 of Full Array.
BA1=0 BA1=0
BA0=0 BA0=1
BA1=0 BA1=0
BA0=0 BA0=1
BA1=0 BA1=0
BA0=0 BA0=1
BA1=1 BA1=1
BA0=0 BA0=1
BA1=1 BA1=1
BA0=0 BA0=1
BA1=1 BA1=1
BA0=0 BA0=1
- Full Array
- 1/2 Array
- 1/4 Array
Partial Self Refresh Area
Temperature Compensated Self Refresh
1. In order to save power consumption, Mobile-DRAM includes the internal temperature sonsor and control units to control the self
refresh cycle automatically according to the two temperature range : Max 40 °C and Max 85 °C(for Extended), Max 70 °C(for
Commercial).
2. If the EMRS for external TCSR is issued by the controller, this EMRS code for TCSR is ginored.
Self Refresh Current (Icc6)
Temperature Range
- S/R
Unit
- E/C
- N/L
Full Array
1/2 of Full Array
1/4 of Full Array
Max 85/70 °C
600
450
400
1500
600
uA
Max 40 °C
450
400
350
B. POWER UP SEQUENCE
1. Apply power and attempt to maintain CKE at a high state and all other inputs may be undefined.
- Apply VDD before or at the same time as VDDQ.
2. Maintain stable power, stable clock and NOP input condition for a minimum of 200us.
3. Issue precharge commands for all banks of the devices.
4. Issue 2 or more auto-refresh commands.
5. Issue a mode register set command to initialize the mode register.
6. Issue a extended mode register set command to define PASR operating type of the device after normal MRS.
EMRS cycle is not mandatory and the EMRS command needs to be issued only when PASR is used.
The default state without EMRS command issued is all full array refreshed.
The device is now ready for the operation selected by EMRS.
For operating with PASR, set PASR mode in EMRS setting stage.
In order to adjust another mode in the state of PASR mode, additional EMRS set is required but power up sequence is not needed
again at this time. In that case, all banks have to be in idle state prior to adjusting EMRS set.
11
May 2004