Harman Kardon AVR 171/230, Service Manual

Page: 121 / 174

W9825G6JH
Publication Release Date: Nov. 29, 2011
- 5 - Revision A04
5. PIN DESCRIPTION
PIN NUMBER PIN NAME FUNCTION DESCRIPTION
23

26, 22,
29

36
A0

A12
Address
Multiplexed pins for row and column address.
Row address: A0

A12. Column address: A0

A8.
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
15, 39
LDQM,
UDQM
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 (+3.3V) 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 (+3.3V)
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.
40 NC No Connection No connection.
Harman Kardon AVR 171 Service Manual
Page 121 of 174