Features
· Fast access time from clock: 5/6/6/6/7 ns Fast clock rate: 166/143/133/125/100 MHz Fully synchronous operation Internal pipelined architecture 1M word x 4-bank Programmable Mode registers - CAS# Latency: 3 - Burst Length: or full page - Burst Type: interleaved or linear burst - Burst stop function Auto Refresh and Self Refresh 4096 refresh cycles/64ms CKE power down mode Single ± 0.3V power supply Interface: LVTTL 54-pin 400 mil plastic TSOP II package
VDD DQ0 VDDQ DQ1 DQ2 VSSQ DQ3 DQ4 VDDQ DQ5 DQ6 VSSQ DQ7 VDD LDQM WE# CAS# RAS# CS# A2 A3 VDD VSS DQ15 VSSQ DQ14 DQ13 VDDQ DQ12 DQ11 VSSQ DQ10 DQ9 VDDQ DQ8 VSS NC/RFU UDQM CLK CKE A5 A4 VSS
The EM638165 SDRAM is a high-speed CMOS synchronous DRAM containing 64 Mbits. It is internally configured as 4 Banks of 1M word x 16 DRAM with a synchronous interface (all signals are registered on the positive edge of the clock signal, CLK). Read and write accesses to the SDRAM are burst oriented; accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. Accesses begin with the registration of a BankActivate command which is then followed by a Read or Write command. The EM638165 provides for programmable Read or Write burst lengths of or full page, with a burst termination option. An auto precharge function may be enabled to provide a self-timed row precharge that is initiated at the end of the burst sequence. The refresh functions, either Auto or Self Refresh are easy to use. By having a programmable mode register, the system can choose the most suitable modes to maximize its performance. These devices are well suited for applications requiring high memory bandwidth and particularly well suited to high performance PC applications.
Clock Cycle time(min.) Access time from CLK(max.) Row Active time(max.) Row Cycle time(min.)
Part Number EM638165TS-8 EM638165TS-10 Frequency 125MHz 100MHz Package TSOP II TSOP II TSOP II TSOP II TSOP II
No. 6, Technology Rd. V, Science-Based Industrial Park, Hsinchu, Taiwan 30077, R.O.C. TEL: (886)-3-5782345 FAX: (886)-3-5778671
Etron Technology, Inc., reserves the right to make changes to its products and specifications without notice.
Table 1. Pin Details of EM638165 Symbol CLK Type Input Description
Clock: CLK is driven by the system clock. All SDRAM input signals are sampled on the positive edge of CLK. CLK also increments the internal burst counter and controls the output registers. Clock Enable: CKE activates(HIGH) and deactivates(LOW) the CLK signal. If CKE goes low synchronously with clock(set-up and hold time same as other inputs), the internal clock is suspended from the next clock cycle and the state of output and burst address is frozen as long as the CKE remains low. When all banks are in the idle state, deactivating the clock controls the entry to the Power Down and Self Refresh modes. CKE is synchronous except after the device enters Power Down and Self Refresh modes, where CKE becomes asynchronous until exiting the same mode. The input buffers, including CLK, are disabled during Power Down and Self Refresh modes, providing low standby power. Bank Select: BA0,BA1 input select the bank for operation. BA1 BA0 Select Bank BANK #A BANK #B BANK #C BANK #D
Address Inputs: A0-A11 are sampled during the BankActivate command (row address A0-A11) and Read/Write command (column address A0-A7 with A10 defining Auto Precharge) to select one location out of the 2M available in the respective bank. During a Precharge command, A10 is sampled to determine if all banks are to be precharged (A10 = HIGH). The address inputs also provide the op-code during a Mode Register Set command. Chip Select: CS# enables (sampled LOW) and disables (sampled HIGH) the command decoder. All commands are masked when CS# is sampled HIGH. CS# provides for external bank selection on systems with multiple banks. It is considered part of the command code. Row Address Strobe: The RAS# signal defines the operation commands in conjunction with the CAS# and WE# signals and is latched at the positive edges of CLK. When RAS# and CS# are asserted "LOW" and CAS# is asserted "HIGH," either the BankActivate command or the Precharge command is selected by the WE# signal. When the WE# is asserted "HIGH," the BankActivate command is selected and the bank designated BS is turned on to the active state. When the WE# is asserted "LOW," the Precharge command is selected and the bank designated BS is switched to the idle state after the precharge operation. Column Address Strobe: The CAS# signal defines the operation commands in conjunction with the RAS# and WE# signals and is latched at the positive edges of CLK. When RAS# is held "HIGH" and CS# is asserted "LOW," the column access is started by asserting CAS# "LOW." Then, the Read or Write command is selected by asserting WE# "LOW" or "HIGH."
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