AN2555 - Application note

Modified features

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1.6

CAN modules

The ST10F269Zx has two CAN modules of the B-CAN type.

The ST10F276Z5 has two CAN modules of the C-CAN type. These modules are functionally compatible

with the modules of the ST10F269Zx.

The C-CAN cells provide additional Message Objects and new functionalities like Time Triggered

Protocol capability. The main difference is that the Message Objects are no longer directly accessed as

memory but are available through a Message Interface. This changes the programming model of the

modules.

In the ST10F269Zx, byte and word accesses are authorized for the CAN modules. In the ST10F276Z5

only word accesses are possible.

1.6.1

Hardware impacts

None.

1.6.2

Software impacts

Re-write the CAN Drivers.

Table 7.

RTCCON Register bits

Bit

Function

Reset

value

RTCSIR

RTC Second Interrupt Request flag (every basic clock unit)

‘0’: the bit was reset less than a Basic Clock unit ago.

‘1’: the interrupt was triggered.

0

RTCSEN

RTC Second interrupt Enable

‘0’: RTC_SecIT is disabled.

‘1’: RTC_SecIT is enabled, it is generated every basic clock unit.

0

RTCAIR

RTC Alarm Interrupt Request flag (when the alarm is triggered)

‘0’: the bit was reset less than n Basic Clock units ago.

‘1’: the interrupt was triggered.

0

RTCAEN

RTC Alarm Interrupt Enable

‘0’: RTC_alarmIT is disabled.

‘1’: RTC_alarmIT is enabled.

0

RTCOFF

RTC Switch Off bit

‘0’: clock oscillator and RTC run even if ST10 is in Power Down mode.

‘1’: clock oscillator is off when ST10 enters Power Down mode. Besides,

setting this bit stop RTC dividers and counters, and registers can be written.

0

OSC

Oscillator Selection Flag

‘0’: the clock oscillator used by the RTC is the Main oscillator.

‘1’: the clock oscillator used by the RTC is the low power 32 kHz oscillator.

U

OFF32

32 kHz Oscillator Switch Off bit

‘0’: The 32 kHz oscillator is enabled. RTC clocked by 32 kHz oscillator (if

there is a valid signal).

‘1’: The 32 kHz oscillator is disabled. RTC clocked by the main oscillator.

0