VI SDRAM CONTROLLER BLOCK: SDRAM INTERFACE
B-VI-2-20
EPSON
S1C33L03 FUNCTION PART
1. The device acting as the external bus master prompts the S1C33 to be prepared to release the bus by means of
an interrupt or some other means.
2. When the S1C33 becomes ready to release the bus, it sets SDRSRF (D5/0x39FFC1) to "1" to place the SDRAM
in self-refresh mode. The S1C33 should stop accessing the SDRAM thereafter.
3. After the SDRAM is placed in self-refresh mode, the external device outputs a bus request.
4. Simultaneously with 3, the external device pulls the SDCKE signal low to ensure that the SDRAM will not be
taken out of self-refresh mode when the bus is released.
5. In response to the bus request, the S1C33 releases the external bus. The external bus, including the SDRAM
interface pins, goes to a high-impedance state.
6. The external bus master takes over control of the SDRAM. If SDRCLK (D3/0x39FFC1) = "1", a clock for the
SDRAM is output from the BCLK pin. Therefore, the external bus master must control the SDRAM
synchronously with that clock. If SDRCLK = "0", BCLK also goes to a high-impedance state at the same time
the bus is released. Therefore, the external bus master supplies a clock to the SDRAM.
Note: If the SDRAM is not accessed after the bus is released, pull the SDRAM’s CKE pin down to low to
keep the self-refresh mode in order to maintain the SDRAM data while the bus is released.
Summary of Contents for CMOS 32-Bit Single Chip Microcomputer S1C33L03
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Page 15: ...S1C33L03 PRODUCT PART ...
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Page 147: ...S1C33L03 FUNCTION PART ...
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Page 149: ...S1C33L03 FUNCTION PART I OUTLINE ...
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Page 152: ...I OUTLINE INTRODUCTION B I 1 2 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 162: ...I OUTLINE LIST OF PINS B I 3 8 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 163: ...S1C33L03 FUNCTION PART II CORE BLOCK ...
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Page 166: ...II CORE BLOCK INTRODUCTION B II 1 2 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 172: ...II CORE BLOCK CPU AND OPERATING MODE B II 2 6 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 176: ...II CORE BLOCK INITIAL RESET B II 3 4 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 224: ...II CORE BLOCK BCU Bus Control Unit B II 4 48 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 262: ...II CORE BLOCK DBG Debug Unit B II 7 2 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 263: ...S1C33L03 FUNCTION PART III PERIPHERAL BLOCK ...
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Page 266: ...III PERIPHERAL BLOCK INTRODUCTION B III 1 2 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 322: ...III PERIPHERAL BLOCK WATCHDOG TIMER B III 5 4 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 415: ...S1C33L03 FUNCTION PART IV ANALOG BLOCK ...
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Page 418: ...IV ANALOG BLOCK INTRODUCTION B IV 1 2 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 434: ...IV ANALOG BLOCK A D CONVERTER B IV 2 16 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 435: ...S1C33L03 FUNCTION PART V DMA BLOCK ...
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Page 438: ...V DMA BLOCK INTRODUCTION B V 1 2 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 492: ...V DMA BLOCK IDMA Intelligent DMA B V 3 18 EPSON S1C33L03 FUNCTION PART THIS PAGE IS BLANK ...
Page 493: ...S1C33L03 FUNCTION PART VI SDRAM CONTROLLER BLOCK ...
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Page 531: ...S1C33L03 FUNCTION PART VII LCD CONTROLLER BLOCK ...
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Page 579: ...S1C33L03 FUNCTION PART Appendix I O MAP ...
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