sed1355 ETC-unknow, sed1355 Datasheet - Page 485

• Manufacturer Part Number: sed1355
• Description: Sed1355 Embedded Ramdac Lcd/crt Controller
• Manufacturer: ETC-unknow

Epson Research and Development
Vancouver Design Center
3.2 Host Bus Interface Signal Descriptions
Interfacing to the NEC VR4121™ Microprocessor
Issue Date: 99/05/05
The SED1355 MIPS/ISA Host Bus Interface requires the following signals.
• BUSCLK is a clock input which is required by the SED1355 Host Bus Interface. It is
• The address inputs AB[20:0], and the data bus DB[15:0], connect directly to the
• M/R# (memory/register) selects between memory or register access. It may be
• Chip Select (CS#) must be driven low by LCDCS# whenever the SED1355 is accessed
• WE1# connects to SHB# (the high byte enable signal from the VR4121) which in
• WE0# connects to WR# (the write enable signal from the VR4121) and must be driven
• RD# connects to RD# (the read enable signal from the VR4121) and must be driven low
• WAIT# connects to LCDRDY and is a signal output from the SED1355 that indicates
• The BS# and RD/WR# signals are not used for the MIPS/ISA Host Bus Interface and
separate from the input clock (CLKI) and is typically driven by the host CPU system
clock.
VR4121 address (ADD[20:0]) and data bus (DAT[15:0]), respectively. MD4 must be
set to select the proper endian mode upon reset.
connected to an address line, allowing system address ADD21 to be connected to the
M/R# line.
by the VR4121.
conjunction with address bit 0 allows byte steering of read and write operations.
low when the VR4121 bus is writing data to the SED1355.
when the VR4121 bus is reading data from the SED1355.
the VR4121 bus must wait until data is ready (read cycle) or accepted (write cycle) on
the host bus. Since VR4121 bus accesses to the SED1355 may occur asynchronously to
the display update, it is possible that contention may occur in accessing the SED1355
internal registers and/or display buffer. The WAIT# line resolves these contentions by
forcing the host to wait until the resource arbitration is complete.
should be tied high (connected to V
DD
).
X23A-G-011-03
SED1355
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