![Sundance Spas SMT398 Скачать руководство пользователя страница 22](http://html1.mh-extra.com/html/sundance-spas/smt398/smt398_user-manual_1395354022.webp)
Version 1.1.1
Page 22 of 38
SMT398 User Manual
And totally independent read and write ports eliminate the need for high-speed bus
turn around. The memory is expected to be clocked at 166 MHz allowing a data
throughput rate of 1.3 GBytes/s.
The memory bank of the SMT398 is composed of 2 devices added in parallel in width
expansion architecture. The address bus, input clocks, R# and W# are common to
both devices. The data buses are not common.
Each chip is available in 3 different sizes (up to 164Mbits chips are expected)
QDR part number
Size in
bits
Size in
Bytes
Actual
Memory
size
Amount
of
memory
per board
8Mb 1MBytes
512kx18
2
MBytes
16Mb 2MBytes
1Mx18
4
MBytes
32Mb
4MBytes 2Mx18 4
MBytes
Table 3: QDR RAM sizes
Due to a board layout issue the total available QDR RAM is 2 Mbytes or 4Mbytes
with the 32Mb chips fitted.
QQ[36:0]
QD[36:0]
QSA[21:0]
QWn/QRn
QC/QCn (input)
QK/QKn (output)
2
2
R = 50 Ohms
V
TERM
=
V
REF/2
R = 50 Ohms
V
T
= V
REF/2
36
36
20
20
C/
C
n
K/
Kn
Ctrl
Ad
dr
D
Q
QDR1
18
18
20
C/
C
n
K/
Kn
Ctrl
Ad
dr
D
Q
QDR2
18
18
Figure 7:SMT398 QDR Width expansion arrangement.
Содержание SMT398
Страница 1: ...SMT398 User Manual...