ST ST7735R - 9.2.2 Read cycle sequence

ST7735R
V0.2 29 2009-08-05
9.2.2 Read cycle sequence
The read cycle (RDX high-low-high sequence) means that the host reads information from LCD driver via interface. The
driver sends data (D[17:0]) to the host when there is a falling edge of RDX and the host reads data when there is a rising
edge of RDX.
Figure 9.2.3 8080-series RDX protocol
Note: RDX is an unsynchronized signal (It can be stopped).
CMD DM PA CMD DM & data Data DataS P
CMD DM PA CMD DM & data Data DataS P
D[17:0]
RESX
CSX
D/CX
RDX
WRX
D[17:0]
Host D[17:0]
Host to LCD
Driver D[17:0]
LCD to Host
“1”
Hi-Z
Read parameter Read display data
CMD: write command code
PA: parameter or display data
Signals on D[17:0], D/CX, R/WX, E
pins during CSX=1 are ignored.
DM PA1 DM & data PA
N-2
PA
N-1
PS
CMD CMDS P
Hi-Z Hi-Z
Hi-Z
Figure 9.2.4 8080-series parallel bus protocol, read data from register or display RAM