
Device configuration and ordering information
ST7L34, ST7L35, ST7L38, ST7L39
Doc ID 11928 Rev 7
15.2.1
Flash option bytes
Table 131.
Option byte 0 description
Bit
Bit name
Function
7
AWUCK
Auto wake up clock selection
0: 32 kHz oscillator (VLP) selected as AWU clock
1: AWU RC oscillator selected as AWU clock.
Note: If this bit is reset, the internal RC oscillator must be selected
(option OSC = 0).
6:4
OSCRANGE
[2:0]
Oscillator range
When the internal RC oscillator is not selected (Option OSC = 1),
these option bits select the range of the resonator oscillator current
source or the external clock source.
000: Typ. frequency range with resonator (LP) = 1~2 MHz
001: Typ. frequency range with resonator (MP) = 2~4 MHz)
010: Typ. frequency range with resonator (MS) = 4~8 MHz)
011: Typ. frequency range with resonator (HS) = 8~16 MHz)
100: Typ. frequency range with resonator (VLP) = 32.768~ kHz)
101: External clock on OSC1
110: Reserved
111: External clock on PB4
Note: OSCRANGE[2:0] has no effect when AWUCK option is set to 0.
In this case, the VLP oscillator range is automatically selected as
AWU clock.
3:2
SEC[1:0]
Sector 0 size definition
These option bits indicate the size of sector 0 as follows:
00: Sector 0 size = 0.5 Kbytes
01: Sector 0 size = 1 Kbyte
10: Sector 0 size = 2 Kbytes
11: Sector 0 size = 4 Kbytes
1FMP_R
Readout protection
Readout protection, when selected provides a protection against
program memory content extraction and against write access to Flash
memory.
Erasing the option bytes when the FMP_R option is selected will cause
the whole memory to be erased first and the device can be
reprogrammed.
Refer to the ST7 Flash Programming Reference Manual and
0: Readout protection off
1: Readout protection on
0FMP_W
Flash write protection
This option indicates if the Flash program memory is write protected.
Warning: When this option is selected, the program memory (and
the option bit itself) can never be erased or programmed again.
0: Write protection off
1: Write protection on
Note: The option bytes have no address in the memory map and are
accessed only in programming mode (for example using a
standard ST7 programming tool). The default content of the Flash
is fixed to FFh.