OTP Memory Operation
C513AO-2E Only
User’s Manual
10-8
05.99
Basic Programming Mode is selected by executing the following steps:
1. With a stable V
DD
, a clock signal is applied to the XTAL pins; the RESET pin is set to “1” level
and the PSEN pin is set to “0” level.
2. PROG, PALE, PMSEL1, and EA/
V
PP
are set to “0” level; PRD, PSEL, and PMSEL0 are set to “1”
level.
3. PSEL is changed from “1” to “0” level and thereafter PROG is switched to “1” level.
4. PMSEL1,0 can now be changed; after EA/V
PP
has been set to
V
IH
high level or to
V
PP
, the OTP
memory is ready for access.
The pins RESET and PSEN must stay at “1” and “0” static signal levels respectively throughout
Programming Mode. With a falling edge of PSEL, the logic states of PROG and EA/
V
PP
are
internally latched. These two signals are now used as a programming write pulse signal (PROG)
and as a programming voltage input pin
V
PP
. After the falling edge of PSEL, PSEL must stay at “0”
state during all programming operations.
Note: If Protection Level 1 to 3 has been programmed (see Section 10.6 ) and Programming Mode
has been left, it is not possible to re-enter Programming Mode.
10.4.2 OTP Memory Access Mode Selection
When the C513AO-2E has been put into Programming Mode using basic programming mode
selection, several Access Modes of the OTP memory programming interface are available. The
conditions for the different control signals of these access modes are listed in Table 10-2.
The Access Modes from the table above are basically selected by setting the two PMSEL1,0 lines
to the required logic level. The PROG and PRD signals are the write and read strobe signals. Data
is transferred via Port 0 and addresses are applied to Port 2.
The following sections describe the details of the different Access Modes.
Table 10-2
Access Modes Selection
Access Mode
EA/
V
PP
PROG
PRD
PMSEL
Address
(Port 2)
Data
(Port 0)
1
0
Program OTP memory byte
V
PP
H
H
H
A0-7
A8-13
D0-7
Read OTP memory byte
V
IH
H
Program OTP lock bits
V
PP
H
H
L
–
D1,D0 see
Read OTP lock bits
V
IH
H
Read OTP version byte
V
IH
H
L
H
Byte addr.
of version byte
D0-7