- Computers & electronics
- Computer components
- System components
- Memory modules
- Transcend
- TS64MLR72V6F
- Data Sheet
Transcend 512MB SDRAM PC133 ECC Registered Memory Datasheet
Add to my manuals
11 Pages
Transcend TS64MLR72V6F is a high-performance PC133 Registered DIMM module designed to enhance system memory and boost overall computing capabilities. With its impressive 512MB capacity and 32M x8 CL3 configuration, this module offers reliable and efficient data processing for various applications. The TS64MLR72V6F operates at a voltage range of 3.0V to 3.6V, providing stable power consumption. Additionally, it features burst mode operation, auto and self-refresh capabilities, and DQM byte masking for enhanced data integrity.
advertisement
T S 6 4 M L R 7 2 V 6 F
Description
The TS64MLR72V6F is a 64M bit x 72 Synchronous
Dynamic RAM high-density memory registered DIMM module. The TS64MLR72V6F consists of 18pcs
16Mx8 bits Synchronous DRAMs, 3pcs drive ICs for input control signal, 1pc PLL and a 2048 bits serial
EEPROM on a 168-pin printed circuit board. The
TS64MLR72V6F is a Dual In-Line Memory Module and is intended for mounting into 168-pin edge connector sockets.
Synchronous design allows precise cycle control with the use of system clock. I/O transactions are possible on every clock cycle. Range of operation frequencies, programmable latencies allow the same device to be useful for a variety of high bandwidth, high performance memory system applications.
Features
• RoHS compliant products.
• Performance Range: PC-133
• Burst Mode Operation.
• Auto and Self Refresh.
• DQM Byte Masking (Read/Write)
• Serial Presence Detect (SPD) with serial EEPROM
• LVTTL compatible inputs and outputs.
• Single 3.3V ± 0.3V power supply.
• MRS cycle with address key programs.
Latency (Access from column address)
Burst Length (1,2,4,8 & Full Page)
Data Sequence (Sequential & Interleave)
• All inputs are sampled at the positive going edge of
the system clock.
Transcend Information Inc.
1
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
Placement
A
B
F
E
G
PCB: 09-0872
D
C
H
T S 6 4 M L R 7 2 V 6 F
Dimensions
Side Millimeters Inches
A 133.35
±0.40 5.250
±0.016
B 65.67
000 2.585
000
C 23.49
000
D 8.89
000
E 15.80
0.925
0.350
0.622
000
000
F 19.80 0.780
G 43.00
±0.20 1.693
±0.008
H 1.27
±0.10
0.050
±0.004
(Refer Placement)
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
Pin Identification
Symbol Function
SREGE
EA0~EA2
SCL
SDA
Vcc
Vss
NC
SA0~SA12
SBA0,SBA1
SD0~SD63
SCB0~SCB7
SCK0
SCKE0
/SCS0~SCS3
/SRAS
/SCAS
/SWE
SDQM0~SDQM7
Address Input
Select Bank Address
Data Input / Output.
Check bit (data-in / data-out)
Clock Input.
Clock Enable Input.
Chip Select Input.
Row Address Strobe
Column Address Strobe
Write Enable
Data (DQ) Mask
Register Enable
Address in EEPROM
Serial PD Clock
Serial PD Add/Data input/output
+3.3 Voltage Power Supply
Ground
No Connection
Transcend Information Inc.
2
T S 6 4 M L R 7 2 V 6 F
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
Pinouts:
Pin
No
Pin
Name
Pin
No
Pin
Name
Pin
No
Pin
Name
Pin
No
Pin
Name
01 Vss
02 DQ0
03 DQ1
04 DQ2
05 DQ3
06 Vcc
07 DQ4
08 DQ5
43 Vss
44 NC
85 Vss 127 Vss
86 DQ32 128 CKE0
45 /CS2 87 DQ33 129 */CS3
46 DQM2 88 DQ34 130 DQM6
47 DQM3 89 DQ35 131 DQM7
48 NC 90 Vcc 132 *A13
49 Vcc
50 NC
91 DQ36
92 DQ37
133 Vcc
134 NC
09 DQ6
10 DQ7
11 DQ8
12 Vss
51 NC 93 DQ38 135 NC
52 *CB2 94 DQ39 136 *CB6
53 *CB3 95 DQ40 137 *CB7
54 Vss 96 Vss 138 Vss
13 DQ9 55 DQ16 97 DQ41 139 DQ48
14 DQ10 56 DQ17 98 DQ42 140 DQ49
15 DQ11 57 DQ18 99 DQ43 141 DQ50
16 DQ12 58 DQ19 100 DQ44 142 DQ51
17 DQ13 59 Vcc
18 Vcc 60 DQ20
101 DQ45
102 Vcc
143 Vcc
144 DQ52
19 DQ14 61 NC 103 DQ46 145 NC
20 DQ15 62 *Vref 104 DQ47 146 *Vref
21 *CB0 63 *CKE1 105 *CB4 147 *REGE
22 *CB1 64 Vss 106 *CB5 148 Vss
23 Vss
24 NC
65 DQ21
66 DQ22
107 Vss
108 NC
149 DQ53
150 DQ54
25 NC
26 Vcc
67 DQ23 109 NC
68 Vss 110 Vcc
151 DQ55
152 Vss
27 /WE 69 DQ24 111 /CAS 153 DQ56
28 DQM0 70 DQ25 112 DQM4 154 DQ57
29 DQM1 71 DQ26 113 DQM5 155 DQ58
30 /CS0 72 DQ27 114 */CS1 156 DQ59
31 NC
32 Vss
73 Vcc
74 DQ28
115 /RAS
116 Vss
157 Vcc
158 DQ60
33 A0
34 A2
35 A4
36 A6
37 A8 79 *CLK2 121 A9
38 A10/AP 80 NC 122 BA0
39 BA1
40 Vcc
81 NC
82 SDA
123 A11
124 Vcc
41 Vcc
42 CLK0
75 DQ29 117 A1
76 DQ30 118 A3
77 DQ31 119 A5
78 Vss 120 A7
83 SCL
84 Vcc
* Please refer Block Diagram
159 DQ61
160 DQ62
161 DQ63
162 Vss
163 *CLK3
164 NC
165 SA0
166 SA1
125 *CLK1 167 SA2
126 *A12 168 Vcc
Transcend Information Inc.
3
T S 6 4 M L R 7 2 V 6 F
Block Diagram
CKE1
/CS1
/CS0
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
CKE0
DQM0 DQM4
DQ7
DQ6
DQ5
DQ4
DQ3
DQ2
DQ1
DQ0
DQM1
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U1
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U10
DQ39
DQ38
DQ37
DQ36
DQ35
DQ34
DQ33
DQ32
DQM5
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U5
DQ15
DQ14
DQ13
DQ12
DQ11
DQ10
DQ9
DQ8
DQM2
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U2
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U11
DQ47
DQ46
DQ45
DQ44
DQ43
DQ42
DQ41
DQ40
DQM6
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U6
DQ23
DQ22
DQ21
DQ20
DQ19
DQ18
DQ17
DQ16
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U3
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U12
DQ55
DQ54
DQ53
DQ52
DQ51
DQ50
DQ49
DQ48
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U7
DQM3 DQM7
DQ31
DQ30
DQ29
DQ28
DQ27
DQ26
DQ25
DQ24
DQM5
DQM1
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U4
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U13
DQ63
DQ62
DQ61
DQ60
DQ59
DQ58
DQ57
DQ56
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U8
CB2
CB6
CB3
CB7
CB1
CB5
CB0
CB4
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U9
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U18
VDD
U1~U18
VSS
Note:
1.U1~U18 are 16Mx8 SDRAM.
2.DQ-to-I/O wiring may be changed per nibble.
3.Unless otherwise noted , resister values are 10 Ohms±5%
SA0~SA12
SBA0~SBA1
/SRAS
/SCAS
/SWE
SCKE0
SCS0
SCKE1
SCS1
SDQM0~SDQM7
CK0
/RESET
P
L
L
SCL
EEPROM
WP
T
E
I
S
R
E
G
R
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
DQM
I/O 0
I/O 1
I/O 2
I/O 3
I/O 4
I/O 5
I/O 6
I/O 7
/CS CKE
U14
/CS CKE
U15
/CS CKE
U16
/CS CKE
U17
U1~U18
Register
SDA
U1~U18
U1~U18
U1~U18
U1~U18
U1~U18
U1~U9
U1~U9
U10~U18
U10~U18
U1~U18
SA0 SA1 SA2
This technical information is based on industry standard data and tests believed to be reliable. However , Transcend makes no warranties, either expressed or implied, as to its accuracy and assumes no liability in connection with the use of this product. Transcend reserves the right to make changes in specifications at any time without prior notice.
Transcend Information Inc.
4
T S 6 4 M L R 7 2 V 6 F
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
ABSOLUTE MAXIMUM RATINGS
Parameter
Voltage on any pin relative to Vss
Voltage on VDD supply to Vss
Storage temperature
Power dissipation
Short circuit current
Operating Temperature
Symbol
VIN, VOUT
VDD, VDDQ
TSTG
Value
-1.0~4.6
-1.0~4.6
-55~+150
Unit
V
V
°C
PD
IOS
18
50
W mA
T A 0~70
Note: Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded.
Functional operation should be restricted to recommended operating condition.
Exposure to higher than recommended voltage for extended periods of time could affect device reliability.
DC OPERATING CONDITIONS AND CHARACTERISTICS
Recommended operating conditions (Voltage referenced to Vss = 0V, T A = 0 to 70 °C)
Parameter Symbol Min Typ Max Unit
Supply voltage
Input high voltage
Input low voltage
V DD 3.0 3.3 3.6 V
V IH 2.0 3.0 DD +0.3 V
Note
1
V IL -0.3 0 0.8 V 2
Output high voltage
Output low voltage
Input leakage current
V
V
I
OH
OL
IL
2.4
-
- - V IOH=-2mA
- 0.4 V IOL=2mA
-10 - 10 uA 3
Note: 1. V
IH (max) = 5.6V AC .The overshoot voltage duration is ≤ 3ns.
2. V IL (min) = -2.0V AC .The undershoot voltage duration is ≤ 3ns.
3. Any input 0V ≤ V
IN
≤ V
DDQ.
Input leakage currents include Hi-Z output leakage for all bi-directional buffers with Tri-State outputs.
Transcend Information Inc.
5
T S 6 4 M L R 7 2 V 6 F
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
CAPACITANCE (V DD = 3.3V, TA = 23 °C, f = 1MHz, V
REF = 1.4V
±200mV)
Parameter
Input capacitance (SA 0 ~SA 12 , SBA 0 ~ SBA 1 )
Input capacitance (/SRAS, /SCAS, /SWE)
Input capacitance (SCKE0)
Input capacitance (SCLK0)
Input capacitance (/SCS0~/SCS3)
Input capacitance (SDQM0~SDQM7)
Data input/output capacitance (SD0~SD63)
Symbol
C IN1
C IN2
C IN3
C IN4
C IN5
C IN6
C OUT
40
30
25
10
Min
85
85
50
45
40
30
15
Max
105
105
65
Data input/output capacitance (SCB0~SCB7)
Operating Current
(One Bank Active)
I CC1
C OUT 1 10 15
1,350 pF
DC CHARACTERISTICS (Recommended operating condition unless otherwise noted, T A = 0 to 70 °C)
Parameter Symbol Test Condition CAS Latency Value Unit Note
Burst Length =1 t RC
≥t
RC (min)
I OL =0mA
Precharge Standby Current in power-down mode
I CC2 P CKE ≤V
IL( max), t CC 3
I CC2 PS CKE & CLK≤V IL( max), t CC =∞ 36
I CC2 N
CKE ≥V
IH( min), /CS ≥V
IH( min), t CC =10ns
Input signals are changed one time during 30ns
Precharge Standby Current in non power-down mode
I CC2 NS CKE≥V
IH( min), CLK ≤V
IL( max), t CC =∞
Input signals are stable
288
252 mA 3 pF pF pF pF
Unit pF pF pF
Active Standby Current in power-down mode
Active Standby Current in non power-down mode
(One Bank Active)
Operating Current
(Bust Mode)
I CC3 P CKE ≤V
IL( max), t CC =10ns
I CC3 PS CKE & CLK≤V IL( max), t CC =∞
I CC3 N CKE ≥V
IH( min), /CS ≥V
IH( min), t CC =10ns
Input signals are changed one time during 20ns
I
I
I CC3 NS CKE ≥V
IH( min), CLK ≤V
IL( max), t CC =∞
Input signals are stable
CC4
CC5
I OL= 0 mA
Page Burst tcc
D = 2CLKs t RC
≥t
RC (min)
108
108
540
450
1,530 mA mA
3
3 mA 1
Refresh Current 2,160 mA 2,3
Self Refresh Current I CC6 CKE 3
Note: Module IDD was calculated on the basis of component IDD and can be differently measured according to DQ loading cap.
Transcend Information Inc.
6
T S 6 4 M L R 7 2 V 6 F
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
AC OPERATING TEST CONDITIONS (V DD = 3.3V
±0.3V, TA = 0 to 70°C)
Parameter Value Unit
AC Input levels (V IH /V IL ) 2.4/0.4
Input timing measurement reference level 1.4 V
Input rise and fall time
Output timing measurement reference level
Output load condition
3.3V
tr/tf=1/1
1.4
See Fig. 2
Vtt=1.4V
ns
V
50 Ohm
Output
870 Ohm
1200 Ohm
50pF
V
OH
(DC)=2.4V, I
OH
=-2mA
V
OL
(DC)=0.4V, I
OL
=2mA
Output Z0=50 Ohm
50pF
(Fig. 1) DC Output Load Circuit (Fig. 2) AC Output Load Circuit
OPERATING AC PARAMETER
(AC operating conditions unless otherwise noted)
Parameter Symbol Value
Row active to row active delay
/RAS to /CAS delay
Row precharge time
Unit Note t RRD (min) 15 1 t RCD (min) 20 1 t RP (min) 20 1
Row active time
Row cycle time
Last data in to new col. address delay
Last data in to row precharge t RAS (min) 45 1 t RAS (max) 100 t RC (min) 65 1 t CDL (min) 1 2 t RDL (min) 2 2
Last data in to burst stop
Col. address to col. address delay t BDL (min) 1 2 t CCD (min) 1 3
4 Number of valid output data CAS latency=3 2 ea
Note: 1. The minimum number of clock cycles is determined by dividing the minimum time required with
clock cycle time, and then rounding off to the next higher integer.
2. Minimum delay is required to complete write in Reg. DIMM
3. All parts allow every cycle column address change.
4. In case of row precharge interrupt, auto precharge and read burst stop.
Transcend Information Inc.
7
T S 6 4 M L R 7 2 V 6 F
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
AC CHARACTERISTICS (AC operating conditions unless otherwise noted)
Refer to the individual component, not the whole module.
Parameter Symbol
Min
Value
Max
Unit Note
CLK cycle time
CLK to valid output delay
Output data hold time
CLK high pulse width
CLK low pulse width
Input setup time
Input hold time
CLK to output in Low-Z
CLK to outputin Hi-Z
CAS latency=3
CAS latency=3
CAS latency=3 t t t
CC
SAC
OH
7.5 ns 1
5.4
2.7 t CH 2.5 t CL 2.5 ns 3 ns 3 t SS 1.5 ns 3 t SH 0.8 ns 3 t SLZ 1 ns 2 t SHZ 5.4 ns 1 CAS latency=3
Note: 1. Parameters depend on programmed CAS latency.
2. If clock rising time is longer than 1ns, (tr/2-0.5)ns should be added to the parameter.
3. Assumed input rise and fall time (tr & tf)= 1ns.
If tr & tf is longer than 1ns, transient time compensation should be considered,
i.e., [(tr + tf)/2-1]ns should be added to the parameter.
Transcend Information Inc.
8
T S 6 4 M L R 7 2 V 6 F
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
SIMPLIFIED TRUTH TABLE
COMMAND SCKEn-1 SCKEn /SCS /SRAS /SCAS /SWE SDQM SBA
0,1
SA
10
/AP SA
12,
A
11
,SA
0
~SA
9
Note
Register Mode Register Set 1,2
Refresh Auto Refresh
Self
Refresh
Entry
Bank Active & Row Adders.
Read &
Column Address
Auto Precharge Disable
Auto Precharge Enable
Write &
Column Address
Auto Precharge Disable
Auto Precharge Enable
Burst Stop
Precharge
Clock Suspend or
Active Power Down
Bank Selection
Both Banks
H
H
H
L
X
L
H X L
H X L
H
L
L
H
X
L
L
H
X
H
H
H
X
H
X
X X
X V
X
Row Address
3
3
3
3
X L 4
H Address
(SA
0
~SA
9
,SA
11
)
4, 5
X L 4
H H L X
X X X X
H
L H L X V L
X H
X
Address
(SA
0
~SA
9
,SA
11
)
X
X
4, 5
6
Precharge Power
Down Mode
Entry
Exit
L
L
L
V
X
H
X
V
V
X
H
X
V
V
X
V
X
H
X
X
X
No Operation Command
L
X
H
X
H
X
H
X X
(V=Valid, X=Don’t Care, H=Logic High, L=Logic Low)
Note: 1. OP Code : Operand Code
SA
0
~SA
11
, SBA
0
~SBA
1
: Program keys. (@MRS)
2. MRS can be issued only at both banks precharge state.
A new command can be issued after 2 CLK cycles of MRS.
3. Auto refresh functions are as same as CBR refresh of DRAM.
The automatically precharge without row precharge command is meant by “Auto”.
Auto/self refresh can be issued only at both banks precharge state.
4. SBA
0
~SBA
1
: Bank select address.
If both SBA
0 and SBA
1 are “Low” at read, write, row active and precharge, bank A is selected.
If both SBA
0
is “Low” and SBA
1
is “High” at read, write, row active and precharge, bank B is selected.
If both SBA
0
is “High” and SBA
1
is “Low” at read, write, row active and precharge, bank C is selected.
If both SBA
0 and SBA
1 are “High” at read, write, row active and precharge, bank D is selected.
If SA
10
/AP is “High” at row precharge, SBA
0
and SBA
1
is ignored and both banks are selected.
5. During burst read or write with auto precharge, new read/write command can not be issued.
Another bank read/write command can be issued after the end of burst.
New row active of the associated bank can be issued at tRP after the end of burst.
6. Burst stop command is valid at every burst length.
7. SDQM sampled at positive going edged of a CLK masks the data-in at the very CLK (Write SDQM latency is 0),
but makes Hi-Z state the data-out of 2 CLK cycles after. (Read SDQM latency is 2)
Transcend Information Inc.
9
T S 6 4 M L R 7 2 V 6 F
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
Serial Presence Detect Specification
Byte No.
0
Serial Presence Detect
Function Described Standard Specification
Number of Bytes Written into Serial Memory 128bytes
1 Total Number of Bytes of S.P.D Memory
3
4
5
6
7
8
Number of Row Addresses on this Assembly
Number of Column Addresses on this Assembly
Number of Module Banks on this Assembly
Data Width of this Assembly
Data Width Continuation
Voltage Interface Standard of this Assembly
256bytes
SDRAM
13
10
2 bank
72bits
0
LVTTL3.3V
9 SDRAM Cycle Time (highest CAS latency)
10 SDRAM Access from Clock (highest CL)
11 DIMM configuration type (non-parity, ECC)
12 Refresh Rate Type
13 Primary SDRAM Width
14 Error Checking SDRAM Width
15 Min Clock Delay Back to Back Random Address
16 Burst Lengths Supported
17 Number of banks on each SDRAM device
18 CAS # Latency
19 CS # Latency
20 Write Latency
21
22
SDRAM Module Attributes
SDRAM Device Attributes: General
7.5ns
5.4ns
ECC
7.8us/Self Refresh
X8
X8
1 clock
1,2,4,8 & Full page
4 bank
3
0 clock
0 clock
Registered DQM, address/control inputs and on-card PLL
Prec All, Auto Prec, R/W
Burst
23 SDRAM Cycle Time (2 nd
highest CL)
24 SDRAM Access from Clock (2 nd
highest CL)
25 SDRAM Cycle Time (3 rd
highest CL)
26 SDRAM Access from Clock (3 rd highest CL)
27 Minimum Row Precharge Time
28 Minimum Row Active to Row Activate
29 Minimum RAS to CAS Delay
30 Minimum RAS Pulse Width
31 Density of Each Bank on Module
32 Command/Address Setup Time
33 Command/Address Hold Time
34 Data Signal Setup Time
35 Data Signal Hold Time
0ns
0ns
0ns
0ns
20ns
15ns
20ns
45ns
256MB
1.5ns
0.8ns
1.5ns
0.8ns
0E
40
15
08
15
08
14
0F
14
2D
00
00
00
00
Vendor Part
80
08
04
0D
0A
75
54
02
82
02
48
00
01
04
04
01
01
08
08
01
8F
16
16
Transcend Information Inc.
10
T S 6 4 M L R 7 2 V 6 F
62 SPD Data Revision Code
63 Checksum for Bytes 0-62
64-71 Manufacturers JEDEC ID Code per JEP-108E
73-90 Manufacturers Part Number
93-94 Manufacturing Date
95-98 Assembly Serial Number
126 Intel Specification Frequency
127 Intel Specification CAS# Latency/Clock Signal Support
128~ Unused Storage Locations
168PIN PC133 Registered DIMM
512MB With 32M X8 CL3
-
JEDEC 2
-
Transcend
T
TS64MLR72V6F
-
By Manufacturer
By Manufacturer
-
-
CL=3 Clock 0
Open
00
02
E9
7F, 4F
54
54 53 36 34 4D 4C
52 37 32 56 36 46
20 20 20 20 20 20
0
Variable
Variable
0
64
84
FF
Transcend Information Inc.
11
advertisement
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project