adv601lc Analog Devices, Inc., adv601lc Datasheet - Page 17

• Manufacturer Part Number: adv601lc
• Description: Ultralow Cost Video Codec
• Manufacturer: Analog Devices, Inc.

DRAM Interface Pins
Name
DDAT[15:0]
DADR[8:0]
RAS
CAS
WE
Host Interface Pins
Name
DATA[31:0]
ADR[1:0]
BE0–BE3
CS
WR
RD
REV. 0
Pins
16
9
1
1
1
Pins
32
2
2
1
1
1
I/O
I/O
O
O
O
O
I/O
I/O
I
I
I
I
I
DRAM Data Bus. The ADV601LC uses these pins for 16-bit data read/write
Host Data Bus. These pins make up a 32-bit wide host data bus. The host
Description
operations to the external 256K 16-bit DRAM. (The operation of the DRAM
interface is fully automatic and controlled by internal functionality of the
ADV601LC.) These pins are compatible with 30 pF loads.
DRAM Address Bus. The ADV601LC uses these pins to form the multiplexed
row/column address lines to the external DRAM. (The operation of the DRAM
interface is fully automatic and controlled by internal functionality of the
ADV601LC.) These pins are compatible with 30 pF loads.
DRAM Row Address Strobe. This pin is compatible with 30 pF loads.
DRAM Column Address Strobe. This pin is compatible with 30 pF loads.
DRAM Write Enable. This pin is compatible with 30 pF loads.
Note that the ADV601LC does not have a DRAM OE pin. Tie the DRAM’s
OE pin to ground.
Description
controls this asynchronous bus with the WR, RD, BE, and CS pins to commu-
nicate with the ADV601LC. These pins are compatible with 30 pF loads.
Host DWord Address Bus. These two address pins let you address the
ADV601LC’s four directly addressable host interface registers. For an illustra-
tion of how this addressing works, see the Control and Write Register Map
figure and Status and Read Register Map figure. The ADR bits permit register
addressing as follows:
ADR1
0
0
1
1
Host Word Enable pins. These two input pins select the words that the
ADV601LC’s direct and indirect registers access through the Host Interface;
BE0–BE1 access the least significant word, and BE2–BE3 access the most
significant word. For a 32-bit interface only, tie these pins to ground, making
all words available.
Some important notes for 16-bit interfaces are as follows:
• When using these byte enable pins, the byte order is always the lowest byte
•
• The ADV601LC advances to the next 32-bit compressed data FIFO location
•
•
•
• The ADV601LC advances to the next 16-bit indirect register after the BE0–BE1
•
•
Host Chip Select. This pin operates as follows:
• LO Qualifies Host Interface control signals
• HI Three-states DATA[31:0] pins
Host Write. Host register writes occur on the rising edge of this signal.
Host Read. Host register reads occur on the low true level of this signal.
to the higher bytes.
after the BE2–BE3 pin is asserted then de-asserted (when accessing the Com-
pressed Data register); so the FIFO location only advances when and if the
host reads or writes the MSW of a FIFO location.
pin is asserted then de-asserted; so the register selection only advances when
and if the host reads or writes the MSW of a 16-bit indirect register.
ADR0
0
1
0
1
–17–
DWord
0
1
2
3
Address Byte Address
0x00
0x04
0x08
0x0C
ADV601LC