26 LCD CONTROLLER (LCDC)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
26-35
Comparison of power-save and normal modes
The differences between power-save and normal modes are summarized in Table 26.8.2.
8.2 Differences between Power-Save and Normal Modes
Table 26.
Item
Power-save mode
Normal
Accessing I/O registers
Enabled
Enabled
Accessing look-up table
Enabled
Enabled
Accessing VRAM
Enabled
Enabled
Display (STN panels)
Inactive
Active
Display (HR-TFT panels)
Inactive
Active
LCDC display-data-fetch operation
Inactive
Active
FPDAT[23:0] signals (STN, HR-TFT panels)
Low
Active
FPSHIFT signal (STN panels)
Low
Active
FPLINE, FPFRAME, FPDRDY signals (STN panels)
Low
Active
FPSHIFT signal (HR-TFT panels)
when FPSHIFT_POL/LCDC_TFTSO register = 0
High
Active
FPSHIFT signal (HR-TFT panels)
when FPSHIFT_POL/LCDC_TFTSO register = 1
Low
Active
FPFRAME signal (HR-TFT panels)
High/Low
Active
FPLINE signal (HR-TFT panels)
High/Low
Active
TFT_CTL0 signal (HR-TFT panels)
High/Low
Active
TFT_CTL1 signal (HR-TFT panels)
High/Low
Active
TFT_CTL2 signal (HR-TFT panels)
High/Low
Active
TFT_CTL3 signal (HR-TFT panels)
Low
Active
Reload Functions
26.9
The LCDC supports two reload functions, Control table reload function and LUT reload function, that reset the
LCDC control registers and look-up tables using the reload data prepared in the memory.
Control table reload function
The control table reload function is used to back up and restore LCDC control register settings.
The table below shows the contents of the reload table used in the control table reload function.
9.1 Reload Table Contents (LCDC Registers)
Table 26.
Address
Control register
Base + 0x00
LCDC Display Mode Register (LCDC_DISPMOD), 0x302060
Base + 0x04
Main Window Display Start Address Register (LCDC_MAINADR), 0x302070
Base + 0x08
Main Screen Address Offset Register (LCDC_MAINOFS), 0x302074
Base + 0x0c
Sub-window Display Start Address Register (LCDC_SUBADR), 0x302080
Base + 0x10
Sub-screen Address Offset Register (LCDC_SUBOFS), 0x302084
Base + 0x14
Sub-window Start Position Register (LCDC_SUBSP), 0x302088
Base + 0x18
Sub-window End Position Register (LCDC_SUBEP), 0x30208c
Base: Reload table start address
The reload table can be located in IVRAM or an external memory, and the start address (Base) can be specified
using RTBL_BADR[31:10]/LCDC_RLDADR register. The low-order 10 bits of the LCDC_RLDADR register
is fixed at 0x0, so the reload table always begins from a 1K-byte boundary address. Two or more reload tables
can be prepared and switched by changing RTBL_BADR[31:10].
When a memory space is allocated to a reload table, the contents shown above must be programmed in the ap-
plication program.
The reload table bit configuration is the same as that of the LCDC control registers.
Writing 1 to CTABRLD/LCDC_RLDCTL register resets the LCDC control registers with the reload table data.
This reload operation should be performed during a vertical non-display period. CTABRLD retains 1 during
reloading and it reverts to 0 when the reloading is completed.
LUT reload function
The LUT reload function is used to replace the look-up table settings. This function is effective when the look-
up table function is enabled (LUTPASS/LCDC_DISPMOD = 0).