Datasheet

20 - SPECIAL FUNCTION REGISTER OVERVIEW ST10F269
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When both CAN are disabled via XPERCON
setting, then any access in the address range
00’EE00h - 00’EFFFh will be directed to external
memory interface, using the BUSCONx register
corresponding to address matching ADDRSELx
register. P4.4 and P4.7 can be used as General
Purpose I/O when CAN2 is not enabled, and P4.5
and P4.6 can be used as General Purpose I/O
when CAN1 is not enabled.
The default XPER selection after Reset is
identical to XBUS configuration of ST10C167:
XCAN1 is enabled, XCAN2 is disabled, XRAM1
(2K Byte compatible XRAM) is enabled, XRAM2
(new 8K Byte XRAM) is disabled.
Register XPERCON cannot be changed after the
global enabling of XPeripherals, i.e. after setting of
bit XPEN in SYSCON register.
In EMUlation mode, all the XPERipherals are
enabled (XPERCON bit are all set).
When the Real Time Clock is disabled (RTCEN =
0), the clock oscillator is switch off if ST10 enters
in power-down mode. Otherwise, when the Real
Time Clock is enabled, the bit RTCOFF of the
RTCCON register allows to choose the
power-down mode of the clock oscillator.
’1’: The on-chip Real Time Clock is enabled and can be accessed.