ISSUED DATE :2006/06/14
REVISED DATE :
Instruction set for the GSC93BC46
Instruction SB
READ
EWEN
ERASE
WRITE
ERAL
WRAL
EWDS
1
1
1
1
1
1
1
Address
OP
Code X8
10
00
11
01
00
00
00
A
6
~ A
0
11xxxxx
A
6
~ A
0
A
6
~ A
0
10xxxxx
01xxxxx
00xxxxx
X16
A
5
~ A
0
11xxxx
A
5
~ A
0
A
5
~ A
0
10xxxx
01xxxx
00xxxx
D
7
~ D
0
D
15
~ D
0
Data
X8
X16
Comment
Reads data stored at specified
memory location.
Write enable command (must be
issued before any erase or write
operation).
Erases memory location A
n
~A
0
Write to memory location A
n
~A
0
Erases all memory locations.
Valid only at V
CC
=4.5V to 5.5V
Write all memory locations.
Valid only at V
CC
=4.5V to 5.5V
Disables all erase or write
instructions
D
7
~ D
0
D
15
~ D
0
Note : The X’s in the address field represent don’t care values and must be clocked.
Instruction set for the GSC93BC56/66
Instruction SB
READ
EWEN
ERASE
WRITE
ERAL
WRAL
EWDS
1
1
1
1
1
1
1
Address
OP
Code X8
10
00
11
01
00
00
00
A
8
~ A
0
X16
A
7
~ A
0
Data
X8
X16
Comment
Reads data stored at specified
memory location.
Write enable command (must be
issued before any erase or write
operation).
Erases memory location A
n
~A
0
Write to memory location A
n
~A
0
Erases all memory locations.
Valid only at V
CC
=4.5V to 5.5V
Write all memory locations.
Valid only at V
CC
=4.5V to 5.5V
Disables all erase or write
instructions
11xxxxxxx 11xxxxxx
A
8
~ A
0
A
8
~ A
0
A
7
~ A
0
A
7
~ A
0
D
7
~D
0
D
15
~D
0
10xxxxxxx 10xxxxxx
01xxxxxxx 01xxxxxx
00xxxxxxx 00xxxxxx
D
7
~D
0
D
15
~D
0
Note : The X’s in the address field represent don’t care values and must be clocked.
Function Description
The GSC93BC46/56/66 support 7 different instructions, which must be clocked serially using the CS, SK and
DI pins. Before sending each of these instructions, the CS pin must be pulled high followed by a START bit
(logic ‘1’). The next sequence includes a 2-bit Op Code and usually an 8 or 16-bit address. The next
description describes the various functions in the chip.
READ (READ):
The Read (READ) instruction includes the Op Code (“10”) followed by the memory address
location to be read. After the instruction and address is sent, the data from the memory location can be clocked
out using the serial output pin DO. The data changes on the rising edge of the clock, so the falling edge can be
used to strobe the output.
Note that during shifting the last address bit, the DO pin is a dummy bit (logic “0”).
ERASE/WRITE (EWEN)):
When the chip is first powered-on, no erase or write instructions can be issued.
Only when the Erase/Write Enable (EWEN) instruction is sent will the system be allowed to write to the chip.
The EWEN command only needs to be issued once after being powered-on. To disable the chip again, the
Erase/Write Disable (EWDS) command can be used.
GSC93BC46/56/66
Page: 4/8
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