C508_01 Datasheet, PDF (247/267 Pages) Infineon Technologies AG – 8-Bit CMOS Microcontroller

C508
OTP Memory Operation
10
OTP Memory Operation
The C508-4E is the OTP version in the C508 microcontroller with a 32 Kbyte One-Time
Programmable (OTP) program memory. Fast programming cycles are achieved (1 byte
in 100 µs) with the C508-4E. Several levels of OTP memory protection can be selected
as well.
10.1
Programming Configuration
During normal program execution, the C508-4E behaves like the C508-4R, which has
32 Kbyte of on-chip ROM. To program the device, the C508-4E must be put into the
programming mode. Typically, this is not done in-system but using special programming
hardware. In the programming mode, the C508-4E operates as a slave device similar to
an EPROM standalone memory device and must be controlled with address/data
information, control lines, and an external 11.5 V programming voltage.
In the programming mode, Port 0 provides the bi-directional data lines and Port 2 is used
for the multiplexed address inputs. The upper address information at Port 2 is latched
with the signal PALE. For basic programming mode selection, the inputs RESET, PSEN,
EA/V_PP, PALE and PMSEL1/0, and PSEL are used. Further, the inputs PMSEL1, 0 are
required to select the access types (for example, program/verify data, write lock bits,
etc.) in the programming mode. In programming mode, V_DD/V_SS and a clock signal at
the XTAL pins must be applied to the C508-4E. The 11.5 V external programming
voltage is input through the EA/V_PP pin.
Figure 10-1 shows the pins of the C508-4E required to control the OTP programming
mode.
V_DD V_SS
P2.0 - 7
PALE
PMSEL0
PMSEL1
XTAL1
XTAL2
Port 2
Port 0
C508-4E
P0.0 - 7
EA/V_PP
PROG
PRD
RESET
PSEN
PSEL
Figure 10-1 Programming Mode Configuration
User’s Manual
10-1
MCP04090
2001-05