¡ Semiconductor

MSM548331

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WRITE RELATED

WCLK : Write Clock

WCLK is a write control clock input. Synchronized with WCLK's rising edge, serial write access into

write ports is executed when WE is high and IE is high.

According to WCLK clocks, the internal counter for the serial address is incremented automatically.

In a write address set cycle, all the write addresses which were input from WXAD are stored into

internal address registers synchronously with WCLK. In this address set cycle, WADE/RX must be

held high and WR/TR must be held low.

In the write address reset cycle, various write address reset modes can be set synchronously with

WCLK. These reset cycles replace complicated serial address control with simple reset cycle control

which requires only one WCLK cycle. It greatly facilitates memory access.

WE : Write Enable

WE is a write enable clock input. WE enables or disables both internal write address pointers and

data-in buffers. When WE is high, the internal write address pointer is incremented synchronously

with WCLK. When WE is low, even if WCLK is input, the internal write address pointer is not

incremented.

DIN0-11 : Data-Ins

DIN0-11 are serial data-ins. Corresponding data-in-buffers are masked by IE.

WR/TR : Write Reset/Write Transfer

WR/TR is a write reset control input. Write address reset modes are defined when WR/TR level is

high according to the "FUNCTION TABLE for write".

When the write operation on a line is terminated, be sure to perform a write transfer operation by

WR/TR in order to store the written data in the write register to corresponding memory cells.

WXINC : Write X Address Increment

WXINCisawriteXaddress(orlineaddress)incrementcontrolinput.Inthewriteaddressresetcycle,

defined by WR/TR high, the write X address (or line address) is incremented when WXINC and

WADE/RX are high.

WADE/RX : Write Address Enable/Write X Address Reset Logic Function

WADE/RX is a dual functional control input. WADE, one of the two functions of WADE/RX, is a

write address enable input. In the write address reset cycle, defined by WR/TR high, X address (or

line address) input from WXAD is latched into internal write X address register synchronously with

WCLK.

WXAD : Write X Address

WXAD is a write X address (or line address) input. WXAD specifies line address. 9 bits of write X

address data are input serially from WXAD.

IE : Input Enable

IE is an input enable which controls the write operation. When IE is high, the input operation is

enabled. When IE is low, the write operation is masked. When WE signal is high, and IE low, the

internal serial write address pointer is incremented on the rising edge of WCLK without actual write

operations. This function facilitates picture in picture function in a TV system.