PCF8813 datasheet(22/72 Pages) PHILIPS

22 / 72 page

2004 Mar 05

Philips Semiconductors

Product speciﬁcation

(67 + 1)

× 102 pixels matrix LCD driver

PCF8813

9.2.2

READ MODE

handbook, full pagewidth

MGU633

SCE

SCLK

SDATA

SDOUT

DB7

D/C

DB6 DB5 DB4

DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0

DB3 DB2

DB1 DB0

D/C

Fig.24 Serial interface (3-line), read mode.

In the read mode of the interface, that the microcontroller

reads data from the PCF8813. To do this the

microcontroller has first to send a command, then the read

status command, and then the PCF8813 will respond by

transmitting data on the SDOUT line. After that, SCE is

required to go HIGH before a new command is sent (see

Fig.24).

The PCF8813 samples the SDATA data at rising SCLK

edges, but shifts SDOUT data at falling SCLK edges. Thus

the microcontroller reads SDOUT data at rising SCLK

edges.

After the read status command has been sent, the SDATA

line must be set to 3-state not later than at the falling SCLK

edge of the last bit.

The 8th read bit is shorter than the others because it is

terminated by the rising SCLK edge (see Fig.24). The last

rising SCLK edge sets SDOUT to 3-state after a delay

time (see time t4 in Fig.44).

PCF8813 Datasheet(PDF) 22 Page - NXP Semiconductors