TMS55166 datasheet(22/70 Pages) TI

22 / 70 page

TMS55165, TMS55166, TMS55175, TMS55176

262144 BY 16-BIT MULTIPORT VIDEO RAM

SMVS463 – DECEMBER 1995

POST OFFICE BOX 1443

• HOUSTON, TEXAS 77251–1443

8-column block write (TMS5517x)

The 8-column block-write function allows up to 128 bits of data to be written simultaneously to one row of the

memory array. This function is implemented as 8 columns

× 8 DQs and repeated in two bytes. In this manner,

each of the two bytes can have up to eight consecutive columns written at a time with up to eight DQs per column

(see Figure 12).

DQ4

DQ14

DQ0

Eight Consecutive Columns of 0 – 511

DQ1

DQ2

DQ3

DQ5

DQ6

DQ7

DQ8

DQ9

DQ10

DQ11

DQ12

DQ13

DQ15

Upper Byte

Lower Byte

One Row of 0 – 511

Figure 12. 8-Column Block-Write Operation

Each byte has an 8-bit column mask to mask off any or all of the eight columns from being written with data.

Nonpersistent write-per-bit or persistent write-per-bit functions can be applied to the block-write operation to

provide write-masking options. Write data (color data) is provided by eight bits from the on-chip color register.

Bits 0 – 7 from the 16-bit write-mask register, bits 0 – 7 from the 16-bit column-mask register, and bits 0 – 7 from

the 16-bit color-data register configure the block write for the lower byte, while bits 8 – 15 control the upper byte

in a similar fashion (see Figure 13).

TMS55166 Datasheet(PDF) 22 Page - Texas Instruments