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S3C4530A Datasheet(PDF) 7 Page - Samsung semiconductor |
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S3C4530A Datasheet(HTML) 7 Page - Samsung semiconductor |
7 / 432 page ![]() S3C4530A PRODUCT OVERVIEW 1-7 Table 1-1. S3C4530A Signal Descriptions (Continued) Signal Pin No. Type Description ADDR[21:0]/ ADDR[10]/AP (1) 117-110, 129-120, 135-132 O Address Bus. The 22-bit address bus, ADDR[21:0], covers the full 4M word address range of each ROM/SRAM, flash memory, DRAM, and the external I/O banks. The 23-bit internal address bus used to generate DRAM address. The number of column address bits in DRAM bank can be programmed 8bits to 11bits use by DRAMCON registers. ADDR[10]/AP is the auto pre-charge control pin. The auto pre- charge command is issued at the same time as burst read or burst write by asserting high on ADDR[10]/AP. XDATA[31:0] 141-136, 154-144, 166-159, 175-169 I/O External (bi-directional, 32-bit) Data Bus. The S3C4530A data bus supports external 8-bit, 16-bit, and 32-bit bus sizes. nRAS[3:0]/ nSDCS[3:0] (1) 94, 91, 90, 89 O Not Row Address Strobe for DRAM. The S3C4530A supports up to four DRAM banks. One nRAS output is provided for each bank. nSDCS[3:0] are chip select pins for SDRAM. nCAS[3:0] nCAS[0]/nSDRAS nCAS[1]/nSDCAS nCAS[2]/CKE (1) 98, 97, 96, 95 O Not column address strobe for DRAM. The four nCAS outputs indicate the byte selections whenever a DRAM bank is accessed. nSDRAS is row address strobe signal for SDRAM. Latches row addresses on the positive going edge of the SDCLK with nSDRAS low. Enable row access and pre-charge. nSDCAS is column address strobe for SDRAM. Latches column addresses on the positive going edge of the SDCLK with nSDCAS low. Enables column access. CKE is clock enable signal for SDRAM. Masks SDRAM system clock, SDCLK to freeze operation from the next clock cycle. SDCLK should be enabled at least one cycle prior to new command. Disable input buffers of SDRAM for power down in standby. nDWE 99 O DRAM Not Write Enable. This pin is provided for DRAM bank write operations. (nWBE[3:0] is used for write operations to the ROM/ SRAM/flash memory banks.) . nECS[3:0] 70, 69, 68, 67 O Not External I/O Chip Select. Four external I/O banks are provided for external memory-mapped I/O operations. Each I/O bank stores up to 16 Kbytes. nECS signals indicate which of the four external I/O banks is selected. nEWAIT 71 I Not External Wait. This signal is activated when an external I/O device or ROM/SRAM/flash bank 0 to 5 needs more access cycles than those defined in the corresponding control register. |