Harman Kardon AVR 70/230, Service Manual

Page: 60 / 89

PRELIMINARY W9864G6JH
Publication Release Date: Jan. 25, 2010
- 5 - Revision P01
5. PIN DESCRIPTION
PIN NUMBER PIN NAME FUNCTION DESCRIPTION
23 ~ 26, 22,
29 ~35
A0
−
A11 Address
Multiplexed pins for row and column address.
Row address: A0
−
A11. Column address: A0
−
A7.
A10 is sampled during a precharge command to
determine if all banks are to be precharged or bank
selected by BS0, BS1.
20, 21 BS0, BS1 Bank Select
Select bank to activate during row address latch time,
or bank to read/write during address latch time.
2, 4, 5, 7, 8, 10,
11, 13, 42, 44,
45, 47, 48, 50,
51, 53
DQ0
−
DQ15
Data
Input/ Output
Multiplexed pins for data output and input.
19
CS
Chip Select
Disable or enable the command decoder. When
command decoder is disabled, new command is
ignored and previous operation continues.
18
RAS
Row Address
Strobe
Command input. When sampled at the rising edge of
the clock RAS , CAS and WE define the operation
to be executed.
17
CAS
Column
Address Strobe Referred to RAS
16
WE
Write Enable
Referred to RAS
39, 15
UDQM
LDQM
Input/output
mask
The output buffer is placed at Hi-Z (with latency of 2)
when DQM is sampled high in read cycle. In write
cycle, sampling DQM high will block the write
operation with zero latency.
38 CLK Clock Inputs
System clock used to sample inputs on the rising
edge of clock.
37 CKE Clock Enable
CKE controls the clock activation and deactivation.
When CKE is low, Power Down mode, Suspend
mode, or Self Refresh mode is entered.
1, 14, 27 V
DD
Power Power for input buffers and logic circuit inside DRAM.
28, 41, 54 V
SS
Ground
Ground for input buffers and logic circuit inside
DRAM.
3, 9, 43, 49 V
DDQ
Power for I/O
buffer Separated power from V
DD
, to improve DQ noise
immunity.
6, 12, 46, 52 V
SSQ
Ground for I/O
buffer Separated ground from V
SS
, to improve DQ noise
immunity.
36, 40 NC No Connection No connection.