ST62T52B Datasheet, PDF (13/68 Pages) STMicroelectronics – 8-BIT OTP/EPROM MCUs WITH A/D CONVERTER, AUTO-RELOAD TIMER AND EEPROM

ST62T52B ST62T62B/E62B
1.4 PROGRAMMING MODES
1.4.1 Option Byte
The Option Byte allows configuration capability to
the MCUs. Option byte’s content is automatically
read, and the selected options enabled, when the
chip reset is activated.
It can only be accessed during the programming
mode. This access is made either automatically
(copy from a master device) or by selecting the
OPTION BYTE PROGRAMMING mode of the
programmer.
The option byte is located in a non-user map. No
address has to be specified.
EPROM Code Option Byte
7
0
PRO- EXTC- PB2-3
TECT NTL PULL
-
WDACT DELAY OSCIL
-
PROTECT. This bit allows the protection of the
software contents against piracy. When the bit
PROTECT is set high, readout of the OTP con-
tents is prevented by hardware. No programming
equipment is able to gain access to the user pro-
gram. When this bit is low, the user program can
be read.
EXTCNTL. This bit selects the External STOP
Mode capability. When EXTCNTL is high, pin NMI
controls if the STOP mode can be accessed when
the watchdog is active. When EXTCNTL is low,
the STOP instruction is processed as a WAIT as
soon as the watchdog is active.
PB2-3 PULL. When set this bit removes pull-up at
reset on PB2-PB3 pins. When cleared PB2-PB3
pins have an internal pull-up resistor at reset.
D4. Reserved. Must be cleared to zero.
WDACT. This bit controls the watchdog activation.
When it is high, hardware activation is selected.
The software activation is selected when WDACT
is low.
DELAY. This bit enables the selection of the delay
internally generated after pin RESET is released.
When DELAY is low, the delay is 2048 cycles of
the oscillator, it is of 32768 cycles when DELAY is
high.
OSCIL. When this bit is low, the oscillator must be
controlled by a quartz crystal, a ceramic resonator
or an external frequency. When it is high, the os-
cillator must be controlled by an RC network, with
only the resistor having to be externally provided.
D0. Reserved. Must be cleared to zero.
The Option byte is written during programming ei-
ther by using the PC menu (PC driven Mode) or
automatically (stand-alone mode)
1.4.2 Program Memory
EPROM/OTP programming mode is set by a
+12.5V voltage applied to the TEST/V_PP pin. The
programming flow of the ST62T62B is described
in the User Manual of the EPROM Programming
Board.
The MCUs can be programmed with the
ST62E6xB EPROM programming tools available
from SGS-THOMSON.
Table 5. ST62T52B/T62B Program Memory Map
Device Address
0000h-087Fh
0880h-0F9Fh
0FA0h-0FEFh
0FF0h-0FF7h
0FF8h-0FFBh
0FFCh-0FFDh
0FFEh-0FFFh
Description
Reserved
User ROM
Reserved
Interrupt Vectors
Reserved
NMI Interrupt Vector
Reset Vector
Note: OTP/EPROM devices can be programmed
with the development tools available from
SGS-THOMSON
(ST62E6X-EPB
or
ST626X-KIT).
1.4.3 . EEPROM Data Memory
EEPROM data pages are supplied in the virgin
state FFh. Partial or total programming of EEP-
ROM data memory can be performed either
through the application software or through an ex-
ternal programmer. Any SGS-THOMSON tool
used for the program memory (OTP/EPROM) can
also be used to program the EEPROM data mem-
ory.
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