TMS55166 datasheet(18/70 Pages) TI

18 / 70 page

TMS55165, TMS55166, TMS55175, TMS55176

262144 BY 16-BIT MULTIPORT VIDEO RAM

SMVS463 – DECEMBER 1995

POST OFFICE BOX 1443

• HOUSTON, TEXAS 77251–1443

4-column block write (TMS5516x)

The 4-column block-write function allows up to 64 bits of data to be written simultaneously to one row of the

memory array. This function is implemented as 4 columns

× 4 DQs and repeated in four quadrants. In this

manner, each of the four one-megabit quadrants can have up to four consecutive columns written at a time with

up to four DQs per column (see Figure 8).

DQ4

DQ14

DQ0

Four Consecutive Columns of 0 – 511

DQ1

DQ2

DQ3

DQ5

DQ6

DQ7

DQ8

DQ9

DQ10

DQ11

DQ12

DQ13

DQ15

4th Quadrant

3rd Quadrant

2nd Quadrant

1st Quadrant

One Row of 0 – 511

Figure 8. 4-Column Block-Write Operation

Each one-megabit quadrant has a 4-bit column mask to mask off any or all of the four 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 four bits from the on-chip color

0 – 3 from the 16-bit color-data register configure the block write for the first quadrant, while bits 4 – 7, 8 – 11,

and 12 – 15 of the corresponding registers control the other quadrants in a similar fashion (see Figure 9).

TMS55166 Datasheet(PDF) 18 Page - Texas Instruments