BAT32G1x9 user manual | Chapter 23 LCD bus interface
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Rev.1.02
(2). 8-bit read
The figure below shows the 8 bits read action in 68 mode.
Figure 23-12 (68
mode: LBTCTL. IMD=1):
Read consecutive
8 bits
timing
LBWST=4,LBCYC=7,LBCTL. TCIS=0
Description: Timing diagrams are for feature description purposes only and have no association with the actual
hardware implementation.
(a) The order of the run
<1> a virtual read of the LBDATA register initiates the reading of 8 bits of data from an external LCD
controller. Busy flag bit LBCTL. BYF was immediately put up. Transmitting flag bits LBCTL. The TPF is
placed on the rising edge of the clock. The data read from LBDATA belongs to the previous transfer data and
can be ignored.
<2> the busy flag bit LBCTL.BYF is cleared when data from the LCD bus interface is sampled into the
LBDATA registers available. The interrupt signal INTLCD outputs the effective level of one clock cycle.
<3> performs a new read of LBDATA before the last transfer completed (no cycle time elapses). The
busy flag bit LBCTL.BYF is immediately set up, but a new transfer begins after the previous transfer is
complete. The in-transit flag LBCTL.TPF remains unchanged. The data read from LBDATA is the first 8bits
LCD data.
<4>, the sampled data is available in LBDATA, and the busy flag bit LBCTL.BYF is cleared.
repeat steps 2 through 4 <5 > until the last 8 bits to be read are sampled.
<6> the last 8 bits are not read from the LBDATA registers, but from LBDATAR to avoid triggering a new
read transfer on the LCD bus.