SED1354 Datasheet, PDF (136/472 Pages) Epson Company – Color Graphics LCD/CRT Controller

Page 128
Epson Research and Development
Vancouver Design Center
13 Power Save Modes
Two Power Save Modes have been incorporated into the SED1354 to accommodate the important
need for power reduction in the hand-held devices market. These modes are hardware suspend and
software suspend.
13.1 Hardware Suspend
• Register read/write disallowed.
• Memory read/write disallowed.
• LCD outputs are forced low (see Note 1 of Section 13.4, “Pin States in Power Save Modes” on
page 129).
• LCDPWR forced to Off state.
• CRT outputs are disabled.
• If suspend mode CBR refresh is selected, all internal modules and clocks except the Memory I/F
are shut down.
• If suspend mode self-refresh or no-refresh is selected, all internal modules and clocks are shut
down.
13.2 Software Suspend
• Register read/write allowed except for RAMDAC registers.
• Memory read/write disallowed.
• LCD outputs are forced low (see Note 1 of Section 13.4, “Pin States in Power Save Modes” on
page 129).
• LCDPWR forced to Off state.
• CRT outputs are disabled.
• If suspend mode CBR refresh is selected, all internal modules and clocks except the Host Bus I/F
and the Memory I/F are shut down.
• If suspend mode self-refresh or no-refresh is selected, all internal modules and clocks except the
Host Bus I/F are shut down.
SED1354
X19A-A-002-16
Hardware Functional Specification
Issue Date: 99/05/18