3 MEMORY MAP, BUS CONTROL
3-6
EPSON
S1C17704 TECHNICAL MANUAL
3.4 Display RAM Area
3.4.1 Display RAM
The display RAM for the on-chip LCD driver is located in the 576-byte area from address 0x80000 to address
0x8055f. The display RAM is accessed in two to five cycles as an eight-bit device. It can be used as a general-
purpose RAM when it is not used for display. See Section 22.5, “Display Memory,” for details of the display
memory.
3.4.2 Access Control for the SRAM Controller
The S1C17704 display RAM is accessed via the exclusive SRAM controller. A MISC register is used to set the
access condition for the SRAM controller.
Setting number of access cycles for the SRAM controller
In order to read/write data from/to the display RAM properly, set the appropriate number of access cycles
according to the CCLK frequency using the SRCYC[1:0] bits (D[1:0]/ MISC_SR register).
0x5321: SRAMC Control Register (MISC_SR)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
SRAMC Control
Register
(MISC_SR)
0x5321
(8 bits)
D7–2
–
reserved
–
–
–
0 when being read.
D1–0
SRCYC[1:0]
SRAMC access cycle
SRCYC[1:0]
Access cycle
0x3
R/W
0x3
0x2
0x1
0x0
5 cycles
4 cycles
3 cycles
2 cycles
D[7:2] Reserved
D[1:0]
SRCYC[1:0]: SRAMC Access Cycle Setup Bits
Sets the number of SRAM (display RAM) controller access cycle.
Table 3.4.2.1 Setting Access Cycles for the SRAM Controller
SRCYC[1:0]
Number of access cycles
CCLK frequency
0x3
5 cycles
8.2 MHz max.
0x2
4 cycles
8.2 MHz max.
0x1
3 cycles
8.2 MHz max.
0x0
2 cycles
6 MHz max.
(Default: 0x3)
Summary of Contents for S1C17704
Page 1: ...TECHNICAL MANUAL S1C17704 CMOS 16 BIT SINGLE CHIP MICROCOMPUTER ...
Page 22: ...1 OVERVIEW 1 10 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 42: ...3 MEMORY MAP BUS CONTROL 3 12 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 82: ...6 INTERRUPT CONTROLLER ITC 6 26 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 108: ...8 CLOCK GENERATOR CLG 8 8 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 112: ...9 PRESCALER PSC 9 4 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 138: ...10 I O PORTS P 10 26 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 156: ...11 16 BIT TIMERS T16 11 18 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 208: ...14 8 BIT OSC1 TIMER T8OSC1 14 16 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 234: ...16 STOPWATCH TIMER SWT 16 14 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 242: ...17 WATCHDOG TIMER WDT 17 8 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 264: ...18 UART 18 22 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 300: ...20 I2C 20 20 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 320: ...21 REMOTE CONTROLLER REMC 21 20 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 360: ...24 ON CHIP DEBUGGER DBG 24 6 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...
Page 362: ...25 BASIC EXTERNAL WIRING DIAGRAM 25 2 EPSON S1C17704 TECHNICAL MANUAL THIS PAGE IS BLANK ...