BBK LD1506SI-2, Руководство по обслуживанию, Страница: 70 / 168

Section Five Function Introduction to IC
3.5.1 function introduction to SDRAM(HY57V641620HGT-7 )U301
The function of SDRAM (U301) in the player is to save program taken out by Mt1389 from FLASH and
information of picture and sound taken out from disc when the player is working to form damping, add the
stability of information output and add anti-vibration of the player. The pin function and real voltage are shown
as the following table:
Pin Name Function
Data
direction
Voltage
when
no disc
Pin Name Function
Data
direction
Voltage
when
no disc
1 VDD 3.3V power supply 3.18 28 VSS Ground 0.01
2 DQ0 Data bus I/O 0.94 29 MA4 Address bus I 1.65
3 VDDQ 3.3V power supply I/O 3.19 30 MA5 Address bus I 1.74
4 DQ1 Data bus I/O 0.9 31 MA6 Address bus I 1.49
5 DQ2 Data bus I/O 1.3 32 MA7 Address bus I 1.22
6 VSSQ Ground 0 33 MA8 Address bus I 0.05
7 DQ3 Data bus I/O 1.2 34 MA9 Address bus I 0.04
8 DQ4 Data bus I/O 1.5 35 MA11 Address bus I 0.04
9 VDDQ 3.3V power supply 3.18 36 NC Blank pin 0.01
10 DQ5 Data bus I/O 0.7 37 CKE Clock enable signal I 1.22
11 DQ6 Data bus I/O 0.45 38 CLK System clock input I 1.68
12 VSSQ Ground 0 39 UDQM Data in/out screen-shielded signal I 2.42
13 DQ7 Data bus I/O 0.8 40 NC Blank pin 0.01
14 VDD 3.3V power supply 3.14 41 VSS Ground 0.01
15 LDQM Data in/out screen-shielded signal I 2.46 42 DQ8 Data bus I/O 0.6
16 WE Write control signal I 3.17 43 VDDQ 3.3V power supply 3.19
17 CAS Line address gatig signal I 3.01 44 DQ9 Data bus I/O 0.91
18 RAS Row address gating signal I 3.13 45 DQ10 Data bus I/O 0.8
19 CS Chip selection signal I 2.95 46 VSSQ Ground 0.01
20 SD-BS0 Section address 0 gating signal I 1.8 47 DQ11 Data bus I/O 0.79
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