CAT15008 Datasheet, PDF (6/15 Pages) Catalyst Semiconductor – Voltage Supervisor with 8-Kb and 16-Kb SPI Serial CMOS EEPROM

CAT15008, CAT15016
Figure 2 shows the maximum pulse duration of
negative-going V_CC transients that do not cause a reset
condition. As the amplitude of the transient goes further
below the threshold (increasing V_TH - V_CC), the
maximum pulse duration decreases. In this test, the
V_CC starts from an initial voltage of 0.5V above the
threshold and drops below it by the amplitude of the
overdrive voltage (V_TH - V_CC).
T_AMB = 25ºC
CAT150xxZ
CAT150xxM
RESET OVERDRIVE V_TH - V_CC [mV]
Figure 2. Maximum Transient Duration without
Causing a Reset Pulse vs. Overdrive Voltage
EMBEDDED EEPROM DESCRIPTION
The CAT15008/16 devices support the Serial Peripheral
Interface (SPI) bus protocol, modes (0,0) and (1,1). The
device contains an 8-bit instruction register. The
instruction set and associated op-codes are listed in
Table 1.
Reading data stored in the CAT15008/16 is accom–
plished by simply providing the READ command and an
address. Writing to the CAT15008/16, in addition to a
WRITE command, address and data, also requires
enabling the device for writing by first setting certain bits
in a Status Register, as will be explained later.
After a high to low transition on the C¯¯S input pin, the
CAT15008/16 will accept any one of the six instruction
op-codes listed in Table 1 and will ignore all other
possible 8-bit combinations. The communication
protocol follows the timing from Figure 3.
Table 1: Instruction Set
Instruction Opcode Operation
WREN
WRDI
RDSR
WRSR
READ
WRITE
0000 0110
0000 0100
0000 0101
0000 0001
0000 0011
0000 0010
Enable Write Operations
Disable Write Operations
Read Status Register
Write Status Register
Read Data from Memory
Write Data to Memory
Figure 3. Synchronous Data Timing
V_IH
CS
V_IL
V_IH
SCK
V_IL
V_IH
SI
VIL
t_CSS
t_WH
t_SU
t_H
VALID IN
V_OH
HI-Z
SO
V_OL
Note: Dashed Line = mode (1, 1) - - - - - -
t_CS
t_CSH
t_WL
t_RI
tFI
t_V
t_HO
t_DIS
HI-Z
Doc. No. 1125 Rev. A
6
© 2007 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice