DS1217M_03 Datasheet, PDF (7/8 Pages) Dallas Semiconductor – Nonvolatile Read/Write Cartridge

DS1217M Nonvolatile Read/Write Cartridge
inputs A8 through A11) must be executed to guarantee that pattern entry starts with the first set of 3 bits. Each set
of address inputs is entered into the DS1217M by executing read cycles. The first 11 cycles must match the exact
bit pattern as shown in Table 2. The last five cycles must match the exact bit pattern for addresses A9, A10, and
A11. However, address line 8 defines which of the 16 banks is to be enabled, or all banks are deselected, as per
Table 3. Switching from one bank to another occurs as the last of the 16 read cycles is completed. A single bank is
selected at any one time. A selected bank will remain active until a new bank is selected, all banks are deselected,
or until power is lost. (See the DS1222 BankSwitch Chip data sheet for more detail.)
Remote Connection through a Ribbon Cable
Existing systems that contain 28-pin bytewide sockets can be retrofitted using a 28-pin DIP plug. The DIP plug,
AMP Part Number 746616-2, can be inserted into the 28-pin site after the memory is removed. Connection to the
cartridge is accomplished via a 28-pin cable connected to a 30-contact card edge connector, AMP Part Number
499188-4. The 28-pin ribbon cable must be right justified, such that positions A1 and B1 are left disconnected. For
applications where the cartridge is installed or removed with power applied, both ground contacts (A1 and B1) on
the card edge connector should be grounded to further enhance data integrity. Access time push-out may occur as
the distance between the cartridge and the driving circuitry is increased.
Table 1. Cartridge Numbering
PART
DS1217M 1/2-25
DS1217M 1-25
DS1217M 2-25
DS1217M 3-25
DS1217M 4-25
DENSITY
64kB x 8
128kB x 8
256kB x 8
384kB x 8
512kB x 8
NO. OF BANKS
2
4
8
12
16
Table 2. Address Input Pattern
ADDRESS
INPUTS
0
1
2
3
4
5
A8
1
0
1
0
0
0
A9
0
1
0
1
1
1
A10
1
0
1
0
0
0
A11
0
1
0
1
1
1
X = See Table 3
Table 3. Bank Select Table
BANK
SELECTED
BANKS OFF
BANK 0
BANK 1
BANK 2
BANK 3
BANK 4
BANK 5
BANK 6
A8 BIT SEQUENCE
11 12 13 14 15
0
X
X
X
X
X
0
0
0
0
1
0
0
0
1
1
0
0
1
0
1
0
0
1
1
1
0
1
0
0
1
0
1
0
1
1
0
1
1
0
BIT SEQUENCE
6
7
8
9 10 11 12 13 14 15
1
1
0
1
0
X
X
X
X
X
0
0
1
0
1
0
0
0
1
1
1
1
0
1
0
1
1
1
0
0
0
0
1
0
1
0
0
0
1
1
BANK
BANK 7
BANK 8
BANK 9
BANK 10
BANK 11
BANK 12
BANK 13
BANK 14
BANK 15
A8 BIT SEQUENCE
1
0
1
1
1
1
1
0
0
0
1
1
0
0
1
1
1
0
1
0
1
1
0
1
1
1
1
1
0
0
1
1
1
0
1
1
1
1
1
0
1
1
1
1
1
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