Rev. 0.1 / Feb. 2004

8

Preliminary

HY5W6B6DLF(P)-xE

4Banks x 1M x 16bits Synchronous DRAM

Power Up and Initialization

Like a Synchronous DRAM, Mobile SDR must be powered up and initialized in a predefined manner. Power must be

pause of 200 usec is required. And a precharge all command will be issued to the Mobile SDR. Then, 8 or more Auto

refresh cycles will be provided. After the Auto refresh cycles are completed, a mode register set(MRS) command will

be issued to program the specific mode of operation (Cas Latency, Burst length, etc.) And a extended mode register

set command will be issued to program specific mode of self refresh operation(PASR). The following these cycles, the

Mobile SDR is ready for normal opeartion.

Programming the registers

Mode Register

The mode register contains the specific mode of operation of the Mobile SDR. This register includes the selection of a

burst length(1, 2, 4, 8, Full Page), a cas latency(1, 2 or 3), a burst type. The mode register set must be done before

any activate command after the power up sequence. Any contents of the mode register be altered by re-programming

the mode register through the execution of mode register set command.

Extended Mode Register

The extended mode register contains the specific features of self refresh opeartion of the Mobile SDR. This register

includes the selection of partial arrays to be refreshed(half array, quarter array, etc.). The extended mode register set

must be done before any activate command after the power up sequence. Any contents of the mode register be altered

by re-programming the mode register through the execution of extended mode register set command.

Bank(Row) Active

The Bank Active command is used to activate a row in a specified bank of the device. This command is initiated by

activating CS, RAS and deasserting CAS, WE at the positive edge of the clock. The value on the BA1 and BA0 selects

the bank, and the value on the A0-A11 selects the row. This row remains active for column access until a precharge

command is issued to that bank. Read and write opeartions can only be initiated on this activated bank after the min-

Read

The READ command is used to initiate the burst read of data. This command is initiated by activating CS, CAS, and

deasserting WE, RAS at the positive edge of the clock. BA1 and BA0 inputs select the bank, A7-A0 address inputs select

the sarting column location. The value on input A10 determines whether or not Auto Precharge is used. If Auto Pre-

charge is selected the row being accessed will be precharged at the end of the READ burst; if Auto Precharge is not

selected, the row will remain active for subsequent accesses.

The length of burst and the CAS latency will be determined by the values programmed during the MRS command.

Write

The WRITE command is used to initiate the burst write of data. This command is initiated by activating CS, CAS, WE

and deasserting RAS at the positive edge of the clock. BA1 and BA0 inputs select the bank, A7-A0 address inputs select

the starting column location. The value on input A10 determines whether or not Auto Precharge is used.

If Auto Precharge is selected the row being accessed will be precharged at the end of the WRITE burst; if Auto Pre-

charge is not selected, the row will remain active for subsequent accesses.