COP8SGE5_14 Datasheet, PDF (20/82 Pages) Texas Instruments – COP8SG Family 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two Comparators and USART

COP8SGE5, COP8SGE7, COP8SGH5
COP8SGK5, COP8SGR5, COP8SGR7
SNOS516E – JANUARY 2000 – REVISED APRIL 2013
The following examples illustrate the declaration of ECON and the User information.
Syntax:
[label:]
.sect econ, conf
.db
value ;1 byte,
;configures options
.db
<user information>
.endsect
; up to 8 bytes
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Example: The following sets a value in the ECON register and User Identification for a COP8SGR728M7. The
ECON bit values shown select options: Power-on enabled, Security disabled, Crystal oscillator with on-chip bias
disabled, WATCHDOG enabled and HALT mode enabled.
.sect econ, conf
.db 0x55
;por, xtal, wd, halt
.db 'my v1.00' ;user data declaration
.endsect
OTP SECURITY
The device has a security feature that, when enabled, prevents external reading of the OTP program memory.
The security bit in the ECON register determines, whether security is enabled or disabled. If the security feature
is disabled, the contents of the internal EPROM may be read.
If the security feature is enabled, then any attempt to externally read the contents of the EPROM will
result in the value FF Hex being read from all program locations Under no circumstances can a secured
part be read. In addition, with the security feature enabled, the write operation to the EPROM program memory
and ECON register is inhibited. The ECON register is readable regardless of the state of the security bit. The
security bit, when set, cannot be erased, even in windowed packages. If the security bit is set in a device in a
windowed package, that device may be erased but will not be further programmable.
If security is being used, it is recommended that all other bits in the ECON register be programmed first. Then
the security bit can be programmed.
ERASURE CHARACTERISTICS
The erasure characteristics of the device are such that erasure begins to occur when exposed to light with
wavelengths shorter than approximately 4000 Angstroms (Å). It should be noted that sunlight and certain types of
fluorescent lamps have wavelengths in the 3000Å - 4000Å range.
After programming, opaque labels should be placed over the window of windowed devices to prevent
unintentional erasure. Covering the window will also prevent temporary functional failure due to the generation of
photo currents.
The recommended erasure procedure for windowed devices is exposure to short wave ultraviolet light which has
a wavelength of 2537 Angstroms (Å). The integrated dose (i.e. UV intensity X exposure time) for erasure should
be a minimum of 15W-sec/cm².
RESET
The devices are initialized when the RESET pin is pulled low or the On-chip Power-On Reset is enabled.
Figure 17. Reset Logic
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