VIS
Overview
Preliminary
VG4616321B/VG4616322B
262,144x32x2-Bit
CMOS Synchronous Graphic RAM
The VG4616321(2) SGRAM is a high-speed CMOS synchronous graphics RAM containing 16M bits. It
is internally configured as a dual 256K x 32 DRAM with a synchronous interface (all signals are registered on
the positive edge of the clock signal, CLK). Each of the 256K x 32 bit banks is organized as 1024 rows by
256 columns by 32 bits. Read and write accesses to the SGRAM 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 VG4616321(2) provides for programmable Read or Write burst lengths of 1, 2, 4, 8, or full page,
with burst termination option. An Auto Precharge function may be enabled to provide a self-timed row pre-
charge that is initiated at the end of the burst sequence. The refresh functions, either Auto or Self Refresh
are easy to use. In addition, it features the write per bit and the masked block write functions.
By having a programmable Mode register and special mode register, the system can choose the best
suitable modes to maximize its performance. These devices are well suited for applications requiring high
memory bandwidth, and when combined with special graphics functions result in a device particularly well
suited to high performance graphics applications.
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Fast access time from clock: 4.5/5/5.5ns
Fast clock rate: 200/166/143 MHz
Fully synchronous operation
Internal pipelined architecture
Dual internal banks(256K x 32-bit x 2-bank)
Programmable Mode and Special Mode registers
- CAS Latency: 1, 2, or 3
- Burst Length: 1, 2, 4, 8, or full page
- Burst Type: interleaved or linear burst
- Burst Read Single Write
- Load Color or Mask register
Burst stop function
Individual byte controlled by DQM0-3
Block write and write-per-bit capability
Auto Refresh and Self Refresh
2048 refresh cycles/32ms
Single + 3.3V
±
0.3V
power supply
Input Reference Voltage : Vref = 1.5V
±
0.2V
Interface: LVTTL and SSTL_3
JEDEC 100-pin Plastic QFP package
Document:1G5-0145
Rev.1
Page 1
VIS
DQ3
V
DDQ
DQ4
DQ5
V
SSQ
DQ6
DQ7
V
DDQ
DQ16
DQ17
V
SSQ
DQ18
DQ19
V
DDQ
V
DD
V
SS
DQ20
DQ21
V
SSQ
DQ22
DQ23
V
DDQ
DQM0
DQM2
WE
CAS
RAS
CS
BS
A8
1
2
3
4
Preliminary
VG4616321B/VG4616322B
262,144x32x2-Bit
CMOS Synchronous Graphic RAM
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Key Specifications
VG4616321/VG4616322
t
CK
t
RAS
t
AC
t
RC
Clock Cycle time(min.)
Row Active time(min.)
Access time from CLK(max.)
Row Cycle time(min.)
DQ29
V
SSQ
DQ30
DQ31
V
SS
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
V
DD
DQ0
DQ1
V
SSQ
DQ2
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
81
82
83
84
50
49
48
47
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
DQ28
V
DDQ
DQ27
DQ26
V
SSQ
DQ24
V
DDQ
DQ15
DQ14
V
SSQ
DQ13
DQ12
V
DDQ
V
SS
V
DD
DQ11
DQ10
V
SSQ
DQ9
DQ8
V
DDQ
NC/Vref
DQM3
DQM1
CLK
CKE
DSF
NC
A9
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
A7
A6
A5
A4
V
SS
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
V
DD
A3
A2
A1
A0
-5/6/7
5/6/7 ns
30/36/40 ns
4.5/5/5.5 ns
45/54/62 ns
Document:1G5-0145
Rev.1
Page 2
VIS
Block Diagram
Preliminary
VG4616321B/VG4616322B
262,144x32x2-Bit
CMOS Synchronous Graphic RAM
CLOCK
CLK
BUFFER
Row Decoder
Column Decoder
1024 X 256 X 32
CELL ARRAY
(BANK #0)
Sense Amplifier
CKE
CS
RAS
CAS
WE
DSF
COMMAND
DECODER
CONTROL
SIGNAL
GENERATOR
DQM0~3
COLUMN
COUNTER
A9
DQs
BUFFER
COLOR
REGISTER
MODE
REGISTER
MASK
REGISTER
DQ0
|
DQ31
A0
~
ADDRESS
BUFFER
A8
BS
SPECIAL
MODE
REGISTER
Sense Amplifier
REFRESH
COUNTER
Row Decoder
Rev.1
1024 X 256 X 32
CELL ARRAY
(BANK #1)
Column Decoder
Document:1G5-0145
Page 3
VIS
Pin Num- Symbol
ber
55
CLK
Preliminary
VG4616321B/VG4616322B
262,144x32x2-Bit
CMOS Synchronous Graphic RAM
Table 1 shows the details for pin number, symbol, type, and description.
Table 1. Pin Description of VG4616321
Type Description
Input
Clock:
CLK is driven by the system clock. All SGRAM input signals are sampled on
the positive edge of CLK. CLK also increments the internal burst counter and con-
trol the output registers.
Input
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 both 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 after exiting the
same mode. The input buffers, including CLK, are disabled during Power Down
and Self Refresh modes providing low standby power.
Input
Bank Select:
BS defines to which bank the BankActivate, Read, Write, or Bank-
Precharge command is being applied. BS is also used to program the 10th bit of
the Mode and Special Mode registers.
Input
Address Inputs:
A0-A9 are sampled during the BankActivate command (row
address A0-A9) and Read/Write command (column address A0-A7 with A9 defin-
ing Auto Precharge) to select one location out of the 256K available in the respec-
tive bank. During a Precharge command, A9 is sampled to determine if both banks
are to be precharged (A9 = HIGH). The address inputs also provide the op-code
during a Mode Register Set or Special Mode Register Set command.
Input
Chip Select:
CS enables (sampled LOW) and disables (sampled HIGH) the com-
mand 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.
Input
Row Address Strobe:
The RAS signal defines the operation commands in con-
junction 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 by BS is turned on to the active state. When the WE is asserted
"LOW", the Precharge command is selected and the bank designated by BS is
switched to the idle state after precharge operation.
Input
Column Address Strobe:
The CAS signal defines the operation commands in
conjunction with the RAS and WE signals, and it 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”.
Input
Write Enable:
The WE signal defines the operation commands in conjunction with
the RAS and CAS signals, and it is latched at the positive edges of CLK. The WE
input is used to select the BankActivate or Precharge command and Read or Write
command.
Input
Define Special Function:
The DSF signal defines the operation commands in
conjunction with the RAS and CAS and WE signals, and it is latched at the positive
edges of CLK. The DSF input is used to select the masked write disable/enable
command and block write command, and the Special Mode Register Set cycle.
54
CKE
29
BS
30-34,
47-51
A0-A9
28
CS
27
RAS
26
CAS
25
WE
53
DSF
Document:1G5-0145
Rev.1
Page 4
VIS
23,56,24,
57
DQM0-
DQM3
97,98,100,
1,3,4,6,7,
60,61,63,
64,68,69,
71,72,9,
10,12,13,
17,18,20,
21,74,75,
77, 78,80,
81, 83, 84
30,36-45,
52,86-95
58
DQ0-
DQ31
Preliminary
VG4616321B/VG4616322B
262,144x32x2-Bit
CMOS Synchronous Graphic RAM
Input
Data Input/Output Mask:
DQM0-DQM3 are byte specific, nonpersistent I/O buffer
controls. The I/O buffers are placed in a high-z state when DQM is sampled HIGH.
Input data is masked when DQM is sampled HIGH during a write cycle. Output data
is masked (two-clock latency) when DQM is sampled HIGH during a read cycle.
DQM3 masks DQ31-DQ24, DQM2 masks DQ23-DQ16, DQM1 masks DQ15-DQ8,
and DQM0 masks DQ7-DQ0.
Input/
Data I/O:
The DQ0-31 input and output data are synchronized with the positive
Output edges of CLK. The I/Os are byte-maskable during Reads and Writes. The DQs also
serve as column/byte mask inputs during Block Writes.
NC
-
No Connect:
These pins should be left unconnected.
NC/Vref -/Input No connect/Input Voltage Reference : It must be unconnected when the LVTTL
interface is used in the SGRAM. It must be applied to Vref (1.5V) when the SSTL-3
interface is used in the SGRAM.
V
DDQ
Supply
DQ Power:
Provide isolated power to DQs for improved noise immunity.
2,8,14,22,
59,67,73,
79
5,11,19,
62,70,76,
82,99
15,35,65,
96
16,46,66,
85
V
SSQ
Supply
DQ Ground:
Provide isolated ground to DQs for improved noise immunity.
V
DD
V
SS
Supply
Power Supply:
+3.3V
Supply
Ground
±
0.3V
Document:1G5-0145
Rev.1
Page 5
Embedded System
京公网安备 11010802033920号
EEWORLD
