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LCD Bus Interface (LCD-I/F)
Chapter 23
Preliminary User’s Manual U17566EE1V2UM00
The external signals are listed in the following table.
23.1.2
LCD Bus Interface access modes
The LCD Bus Interface can access the external LCD Controller/Driver in two
different modes. The mode is selected by the bit LBCTL0.IMD.
• mod80
The control signals WR (DBWR) and RD (DBRD) are used to control the
external LCD Controller/Driver.
• mod68
The control signals R/W (DBWR) and E (DBRD) are used to control the
external component.
The level of E depends on the setting of the bit LBCTL0.EL0:
– EL0=0: E is active high; data is read/written on the falling edge.
– EL0=1: E is active low; data is read/written on the rising edge.
23.1.3
Access types to the LBDATA0 register
Access to the LBDATA0 register can be performed as:
• Byte access (8-bit)
• Halfword access (16-bit)
• Word access (32-bit)
Note
1.
Every access must address the base address of the LBDATA0 register.
Access to the individual bytes within the register is prohibited.
2.
Before writing to or reading from the LBDATA0 register or reading the
LBDATAR0 register, always make sure that the busy flag LBCTL0.BYF is
zero.
(1)
Write operation
If there is no transfer in progress on the external bus interface, the new data is
immediately transferred to the external LCD controller. If there is a transfer in
progress, the new data is transferred after the current transfer has completed.
One, two or four bytes are transferred through the bus interface, depending on
how LBDATA0 was accessed (byte, halfword, or word).
The write timing on the external bus interface is determined by the number of
wait cycles (LBWST0.WST[4:0]), the cycle time (LBCYC0.CYC[5:0]) and the
selected clock (LBCTL0.LBC00 and LBCTL0.LBC01).
Table 23-1
LCD Bus Interface external connections
Signal
name
I/O
Active
level
Reset
level
Function
DBWR
O
L
H
mod80: Write strobe (WR)
mod68: Read/Write (R/W)
DBRD
O
L
a
a)
The active level of E in mod68 is controlled by the bit LBCTL0.EL0.
H
mod80: Read strobe (RD)
mod68: E strobe (E)
DBD[7:0]
I/O
L
LCD data bus
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