ssd1908 Solomon Systech Limited:, ssd1908 Datasheet - Page 129

• Manufacturer Part Number: ssd1908
• Description: Lcd Drivers,lcd Controllers
• Manufacturer: Solomon Systech Limited:

12 Power Saving Mode
Power Saving Mode is incorporated into the SSD1908 to accommodate the need for power reduction in the hand-
held device market. This mode is enabled via the Power Saving Mode Enable bit (REG[A0h] bit 0).
Power Saving Mode power down the panel and stop display refresh accesses to the display buffer.
Note :
1
controlled is indicated by the Memory Controller Power Saving Status bit (REG[A0h] bit 3). For Power Saving
Status AC timing, see Section 10.3.3 “Power Saving Status”.
2
information on CF3, see Table 5-6 : Summary of Power-On/Reset Options.
3
After reset, the SSD1908 stays in Power Saving Mode. Software must initialize the chip (i.e. programs all registers)
and then clear the Power Saving Mode Enable bit.
13 Frame Rate Calculation
The following formula is used to calculate the display frame rate.
Where:
FrameRate
SSD1908
When Power Saving mode is enabled, the memory controlled is powered down. The status of the memory
GPIO Pins are configured using the configurations pin CF3 which is latched on the rising edge of RESET#. For
GPIOs can be accessed and if configured as outputs can be changed.
GPIO Pins configured as GPIOs Access Possible ?
f
HT
VT
PCLK
Look-Up Table Registers Access Possible?
=
GPIO3:0 Pins configured for HR-TFT
(
HT
Sequence Controller Running?
f
PCLK
Rev 1.0
)
x
Memory Access Possible?
(
VT
LCD Interface Outputs
IO Access Possible?
)
Display Active?
= PCLK frequency (Hz)
= Horizontal Total
= ((REG[12h] bits 6-0) + 1) x 8 Ts
= Vertical Total
= ((REG[19h] bits 1-0, REG[18h] bits 7-0) + 1) Lines
PWMCLK
P 119/119
Table 12-1 : Power Saving Mode Function Summary
Oct 2003
2
2
Software Power Saving
Forced Low
Forced Low
Stopped
Yes
Yes
Yes
No
No
No
1
3
Solomon Systech
Normal
Active
Active
Active
Yes
Yes
Yes
Yes
Yes
Yes