Power Saving; Registers; Power Save Modes; Power Save Mode 1 - Epson S1D13503 Series Technical Manual

EPSON

5.6 Power Saving

The following section introduces the power saving capabilities of the S1D13503. A detailed descrip-
tion of the Power Save Register is provided, followed by a description of the power save modes.

Registers

Register bits discussed in this section are highlighted.
AUX[03] Mode Register 1
I/O address = 0011b, Read/Write
PS
Bit 1
bits 7–6 PS Bits [1:0]
Selects the Power Save Modes as shown in the following table. The PS bits [1:0] go low
on RESET.
For more details refer to "Power Save Modes" in the S1D13503 Hardware Functional
Specification.

Power Save Modes

Two software-controlled Power Save Modes have been incorporated into the S1D13503 to accom-
modate the important need for power reduction in the hand-held devices market. These modes can
be enabled by setting the 2 Power Save bits (AUX[03h] bits 7–6).
The various settings are:

Power Save Mode 1

Power Save Mode 1 would typically be used when power savings are required and display memory
accesses may occur. The disadvantage is that since the oscillator is running, this mode consumes
more power that Power Save Mode 2.

Power Save Mode 2

Power Save Mode 2 is typically used when display memory accesses would not occur.

Power Save Mode Function Summary

Function
Display Active?
I/O Access Possible?
Memory Access Possible?
Sequence Controller Running?
Internal Oscillator Disabled?
Notes: 1. When programming the PS bits perform a read/modify/write operation so as not to destroy any
other data in the register.
2. Refer to the programming example in "Advanced Functions" on page 51.
2-40
PS LCD Signal
Bit 0 State
Table 5-2 Power Save Mode Selection
PS1 PS0
0 0
0 1
1 0
1 1
Table 5-3 Power Save Mode Selection
Bit 7 Bit 6
0 0
0 1
1 0
1 1
Table 5-4 Power Save Mode Function Summary
Normal
(Active)
LUT LCD Data
Bypass Width Bit 1
Mode Activated
Normal Operation
Power Save Mode 1
Power Save Mode 2
Reserved
Mode Activated
Normal Operation
Power Save Mode 1
Power Save Mode 2
Reserved
Power Save Mode (PSM)
PSM1
State 1
Yes No
Yes Yes
Yes Yes
Yes No
No No
BW / Color Mode
256 colors
PSM2
State 2
No No
Yes Yes
No No
No No
No Yes
S18A-G-002-02
Line Byte
Count Bit 8