VIS
Overview
Preliminary
VG4632321A
524,288x32x2-Bit
CMOS Synchronous Graphic RAM
The VG4632321A SGRAM is a high-speed CMOS synchronous graphic RAM containing 32M bits. It is
internally configured as a dual 512K x 32 DRAM with a synchronous interface (all signals are registered on
the positive edge of the clock signal, CLK). Each of the 512K x 32 bit bank is organized as 2048 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 VG4632321A 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 precharge
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.
Pin Assignment (Top View)
DQ29
V
SSQ
DQ30
DQ31
V
SS
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
V
DD
DQ0
DQ1
V
SSQ
DQ2
Features
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
A9
1
2
3
4
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
81
82
83
84
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Fast access time from clock: 4.5/5/5.5/6/7ns
Fast clock rate: 222/200/183/166/143MHz
Fully synchronous operation
Internal pipelined architecture
Dual internal banks(512K 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
Interface: LVTTL
JEDEC 100-pin Plastic QFP package
80
79
78
77
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
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
DQ25
DQ24
V
DDQ
DQ15
DQ14
V
SSQ
DQ13
DQ12
V
DDQ
V
SS
V
DD
DQ11
DQ10
V
SSQ
DQ9
DQ8
V
DDQ
NC
DQM3
DQM1
CLK
CKE
DSF
NC
A8/AP
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
50
49
48
47
A7
A6
A5
A4
V
SS
A10
NC
NC
NC
NC
NC
NC
NC
NC
NC
V
DD
A3
A2
A1
A0
Key Specifications
VG4632321A
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.)
-4.5/-5/-5.5/-6/-7
4.5/5/5.5/6/7 ns
40/40/40/42/42 ns
4/4.5/5/5.5/6 ns
55/55/56.5/60/62 ns
Document:
Rev.1
Page 1
VIS
Block Diagram
Preliminary
VG4632321A
524,288x32x2-Bit
CMOS Synchronous Graphic RAM
CLOCK
CLK
BUFFER
Row Decoder
Column Decoder
2048 X 256 X 32
CELL ARRAY
(BANK #0)
Sense Amplifier
CKE
CS
RAS
CAS
WE
DSF
COMMAND
DECODER
CONTROL
SIGNAL
GENERATOR
DQM0~31
COLUMN
COUNTER
A8
DQs
BUFFER
COLOR
REGISTER
MODE
REGISTER
MASK
REGISTER
DQ0
|
DQ31
A0
~
ADDRESS
BUFFER
REFRESH
COUNTER
Row Decoder
Rev.1
A7
A9
A10
BS
SPECIAL
MODE
REGISTER
Sense Amplifier
2048 X 256 X 32
CELL ARRAY
(BANK #1)
Column Decoder
Document:
Page 2
VIS
Pin Num- Symbol
ber
55
CLK
Type Description
Preliminary
VG4632321A
524,288x32x2-Bit
CMOS Synchronous Graphic RAM
Table 1 shows the details for pin number, symbol, type, and description.
Table 1. Pin Description of VG4632321A
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
control 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-A10 are sampled during the BankActivate command (row
address A0-A10) and Read/Write command (column address A0-A7 with A8
defining Auto Precharge) to select one location out of the 512K available in the
respective bank. During a Precharge command, A8 is sampled to determine if both
banks are to be precharged (A8 = 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
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.
Input
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 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,
45,47-51
A0-A10
28
CS
27
RAS
26
CAS
25
WE
53
DSF
Document:
Rev.1
Page 3
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,
52,58,
86-95
2,8,14,22,
59,67,73,
79
5,11,19,
62,70,76,
82,99
15,35,65,
96
16,46,66,
85
DQ0-
DQ31
Preliminary
VG4632321A
524,288x32x2-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.
V
DDQ
Supply
DQ Power:
Provide isolated power to DQs for improved noise immunity.
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:
Rev.1
Page 4
VIS
Operation Mode
Command
State
Preliminary
VG4632321A
524,288x32x2-Bit
CMOS Synchronous Graphic RAM
Fully synchronous operations are performed to latch the commands at the positive edges of CLK. Table 2
shows the truth table for the operation commands.
Table 2. Truth Table (Note(1), (2))
CKEn-1 CKEn DQM
(7)
BS
A8
A0-7
A9,
A10
V
V
X
X
V
V
V
V
V
V
V
V
X
X
X
X
X
X
CS
RAS CAS
WE
DSF
BankActivate & Masked Write Disable
BankActivate & Masked Write Enable
BankPrecharge
PrechargeAll
Write
Block Write Command
Write and AutoPrecharge
Block Write and AutoPrecharge
Read
Read and AutoPrecharge
Mode Register Set
Special Mode Register Set
No-Operation
Burst Stop
Device Deselect
AutoRefresh
SelfRefresh Entry
SelfRefresh Exit
Idle
(3)
Idle
(3)
Any
Any
Active
(3)
Active
(3)
Active
(3)
Active
(3)
Active
(3)
Active
(3)
Idle
Idle
(5)
Any
Active
(4)
Any
Idle
Idle
Idle
(SelfRefresh)
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
H
L
H
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
V
V
V
X
V
V
V
V
V
V
V
X
X
X
X
X
X
X
V
V
L
H
L
L
H
H
L
H
L
X
X
X
X
X
X
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
H
L
L
H
L
L
L
L
L
H
H
H
H
H
H
L
L
H
H
X
L
L
X
H
X
X
H
X
X
H
X
X
H
H
H
H
L
L
L
L
L
L
L
L
H
H
X
L
L
X
H
X
X
H
X
X
H
X
X
H
H
L
L
L
L
L
L
H
H
L
L
H
L
X
H
H
X
H
X
X
H
X
X
H
X
X
L
H
L
L
L
H
L
H
L
L
L
H
X
L
X
L
L
X
X
X
X
L
X
X
L
X
X
Clock Suspend Mode Entry
Power Down Mode Entry
Active
Any
(6)
Active
Any
(Power-
Down)
Active
Active
H
H
L
L
X
X
X
X
X
X
X
X
X
H
L
Clock Suspend Mode Exit
Power Down Mode Exit
L
L
H
H
X
X
X
X
X
X
X
X
X
H
L
Data Write/Output Enable
Data Write/Output Disable
H
H
X
X
L
H
X
X
X
X
X
X
X
X
Note: 1. V = Valid X = Don’t Care L = Low level H = High level
2. CKEn signal is input level when commands are provided.
CKEn-1 signal is input level one clock cycle before the commands are provided.
3. These are states of bank designated by BS signal.
4. Device state is 1, 2, 4, 8, and full page burst operation.
5. The Special Mode Register Set is also available in Row Active State.
6. Power Down Mode can not entry in the burst operation.
When this command assert in the burst cycle, device state is clock suspend mode.
7. DQM0-3
Document:
Rev.1
Page 5
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