isd-t360sb ETC-unknow, isd-t360sb Datasheet - Page 16

• Manufacturer Part Number: isd-t360sb
• Manufacturer: ETC-unknow

ISD-T360SB
NAND Flash (Samsung, Toshiba)
The VoiceDSP processor supports up to four NAND
interface Flash memory devices for storing mes-
sages. A flash device with the NAND interface uses
a single 8bit I/O port to set the address and ac-
cess the data. The ISD-T360SB supports three types
of Flash volumes (4Mbit, 8Mbit and 16Mbit as list-
ed inTable 1-4) while all the connected Flash de-
vices must be of the same type. Ports B and C are
used to connect ISD-T360SB to the Flash devices
using port B for address and data transfer and port
C for communication control and chip select.
Connecting less than four Flash devices requires
connecting the Flash devices sequentially, start-
ing from PC4 up to PC7 (see Figure 1-7). Upon ini-
tialization, the ISD-T360SB scans the flash devices
to detect defected blocks. The defected blocks
are marked in a special map, which is located in
the last block of each device.
Flash Endurance
A Flash memory may be erased a limited number
of times. To maximize the Flash use, the memory
manager utilizes the Flash’s blocks evenly (i.e.,
each block is erased more or less the same num-
ber of times), to ensure that all blocks have the
same lifetime. Refer to the respective Flash mem-
ory device data sheets for specific endurance
specifications.
A VoiceDSP processor message uses at least one
block. The maximum recording time depends on
four factors:
1-8
1. The basic compression rate (4.7 Kbit/s, 6.7
2. The amount of silence in the recorded
3. The number of bad blocks
4. The number of recorded messages. (The
Kbit/s or 8.7 Kbit/s).
speech
basic memory allocation unit for a mes-
sage is a 4-Kbyte block, which means that
half a block, on average, is wasted per re-
corded message.)
Table 1-5:
Rom interface
IVS vocabularies can be stored in either Flash
memory and/or ROM. The VoiceDSP processor
supports IVS ROM devices through an Expansion
Memory mechanism. Up to 64 Kbytes (64K x 8) of
Expansion Memory are directly supported. Never-
theless, the processor uses bits of the on-chip port
(PB) to further extend the 64 Kbytes address space
up to 0.5 Mbytes address space.
ROM is connected to the VoiceDSP processor us-
ing the data bus, D(0:7), the address bus, A(0:15),
the extended address signals, EA(16:18), and Ex-
pansion Memory Chip Select, EMCS, controls. The
number of extended address pins to use may
vary, depending on the size and configuration of
the ROM. ISD-T360SB configured with NAND Flash
memory cannot support extension ROM.
4 Mbit
4 Mbit
4 Mbit
8 Mbit
8 Mbit
8 Mbit
16 Mbit
16 Mbit
16 Mbit
32 Mbit
32 Mbit
32 Mbit
Memory Size
Recording Time with No Silence
Compression
4.7 Kbit/s
6.7 Kbit/s
8.7 Kbit/s
4.7 Kbit/s
6.7 Kbit/s
8.7 Kbit/s
4.7 Kbit/s
6.7 Kbit/s
8.7 Kbit/s
4.7 Kbit/s
6.7 Kbit/s
8.7 Kbit/s
Compression
Rate
Voice Solutions in Silicon
14.5 Minutes
10.2 Minutes
7.8 Minutes
29.1Minutes
20.4 Minutes
15.7 Minutes
58.1Minutes
40.8 Minutes
31.4 Minutes
116.2 Minutes
91.5 Minutes
62.8Minutes
Total Recording
1—HARDWARE
Time
™