pcf8814 NXP Semiconductors, pcf8814 Datasheet - Page 19

• Manufacturer Part Number: pcf8814
• Description: Pcf8814 65 X 96 Pixels Matrix Lcd Driver
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9.2.2
In the read mode of the interface the microcontroller reads
data from the PCF8814. To do so, the microcontroller first
has to send a command, the read status command, and
then the following byte is transmitted in the opposite
direction by using SDO (see Fig.21). After that, SCE is
required to go HIGH before a new command is sent.
The PCF8814 samples the SDIN data at rising SCLK
edges, but shifts SDO data at falling SCLK edges. Thus
the microcontroller reads SDO data at rising SCLK edges.
9.2.3
Regardless of which serial interface is used there are five
bits, ID1 to ID4 and VM, that can be read and also one
temperature register. For the bits, one bit is transmitted per
byte read and is selected by issuing the appropriate Read
Table 2 Read data format
Note
1. X = undefined.
Table 3 Temperature sensor
Note
1. X = undefined.
2003 Mar 13
handbook, full pagewidth
65
D7
D7
X
X
SCLK
SDIN
SDO
SCE
R
R
96 pixels matrix LCD driver
EAD MODE
EAD DATA FORMAT
D/C
TD6
D6
D6
B
DB7
DB6 DB5 DB4
TD5
D5
D5
B
Fig.21 Read mode 3-line serial interface.
DB3 DB2 DB1 DB0
TD4
D4
D4
B
19
After the read status command has been sent, the SDIN
line must be set to 3-state not later then at the falling SCLK
edge of the last bit (see Fig.21).
The 8th read bit is shorter than the others because it is
terminated by the rising edge of SCLK (see Fig.45). The
last rising SCLK edge sets SDO to 3-state after the delay
time t
instruction from the instruction set. The format for the read
bit, B, is shown in Table 2.
Sending the instruction to read back the temperature
sensor will select the status byte shown in Table 3.
DB7 DB6 DB5 DB4 DB3 DB2 DB1
TD3
D3
D3
B
4
.
TD2
D2
D2
B
TD1
DB0
D1
D1
B
Objective specification
PCF8814
MBL587
D/C
TD0
D0
D0
B