Datasheet


    
SLIS056A − FEBRUARY 1995 − REVISED MARCH 1996
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443
• HOUSTON, TEXAS 77251−1443
PRINCIPLES OF OPERATION
SCLK
t
su1
123X
t
wL(SCLK)
t
wH(SCLK)
t
w
t
su(SDI)
t
h(SDI)
t
pd1
t
pd3
t
pd2
MSB LSB
3-STATE
MSB LSB
3-STATE
CS
SDI
SDO
Figure 1. Switching Characteristics
serial interface
Control information is transferred into the TPIC2603 through the serial interface. The serial interface consists
of a serial clock (SCLK), chip select (CS
), serial data input (SDI), and serial data output (SDO). Serial data is
shifted, most significant bit (MSB) first, into the SDI shift register on the rising edge of the first SCLK after CS
has transited from high to low. The controller must shift either eight bits or sixteen bits of data into the device
with the last six bits of input data containing control information for the output drivers. Data bits preceeding the
output control information should be set to 0. A low-to-high transition on CS
latches the contents of the last six
bits of the serial shift register into the output buffer. A low input to SDI turns the corresponding parallel output
OFF and a high input will turn the output ON (see Figure 2).
12345678
DRAIN5 OFF
DRAIN4 ON
DRAIN3 ON
DRAIN2 OFF
DRAIN1 OFF
DRAIN0 ON
0
SCLK
CS
SDI
NEW DATA
Figure 2. Serial Input Control