Collection of Product FAQs
Author: Kano Tomoo
Date: 98/11/12 (Thursday) 10:17 (modified: 99/01/13)
<Information level>
A:
Public (Printing O.K.)
D (Technical terms)
Index:
<Product>
Division name: 01 IC
Category 1:
12 Memory
Category 2:
Cal. No.:
2. Serial EEPROM
Overall
Related documents:
Question:
What about the basic terms (memory protect, reset, CS)?
Answer:
Memory protect, reset →S-29xx1A, S-29x94A, S-29x55A
Function for prohibiting a write command from being executed in a certain region of the memory space.
This function is enabled by controlling the protect or reset input pin (select/deselect protect). This reset
prevents the microcomputer from running uncontrollably and also prevents false-writes caused by noise
in order to protect data.
Ex.: Storage of ID codes and product shipment adjustment data
(Note) S-29xx1A and S-29x94A protect 50% of memory, starting with the leading address.
CS, /CS (/CS: S-29x55A, S-29x94A)
CS is an input pin used to select the execution of a command. It is selected using “H” and deselected
using “L” (the reverse is true for /CS)
→ /CS is useful on the interface of the microcomputer (L active is mainly used for the microcomputer).
Malfunction, however, is likely to be caused by noise upon power-on if a command is executed at the
GND level.
CS
SK
DI
29 30 31 32 33
1
2
3
4
5
6
7
8
9
*
10 11 12 13 14 15 16 17 18 19
34
47 48 49 50
45 46
*
A7 A6 A5 A4 A3 A2 A1 A0
X
X
X
1
0
0
0
Hi-Z
Hi-Z
D1 D1 D1
DO
D2 D1 D0 D1 D1 D1
A7A6A5A4A3A2A1A0+1
D2 D1 D0 D1 D1 D1
A7A6A5A4A3A2A1A0+2
43
SII [ SEIKO INSTRUMENTS INC ]
