Datasheet

C505/C505C/C505A/C505CA
Data Sheet 18 12.00
Special Function Registers
The registers, except the program counter and the four general purpose register banks, reside in
the special function register area. The special function register area consists of two portions : the
standard special function register area and the mapped special function register area. Five special
function register of the C505 (PCON1,P1ANA, VR0, VR1, VR2) are located in the mapped special
function register area. For accessing the mapped special function register area, bit RMAP in special
function register SYSCON must be set. All other special function registers are located in the
standard special function register area which is accessed when RMAP is cleared (“0“).
The registers and data locations of the CAN controller (CAN-SFRs) are located in the external data
memory area at addresses F700
H
to F7FF
H
..
Special Function Register SYSCON (Address B1
H
) Reset Value : XX100X01
B
(C505CA only) Reset Value : XX100001
B
As long as bit RMAP is set, mapped special function register area can be accessed. This bit is not
cleared by hardware automatically. Thus, when non-mapped/mapped registers are to be accessed,
the bit RMAP must be cleared/set respectively by software.
All SFRs with addresses where address bits 0-2 are 0 (e.g. 80
H
, 88
H
, 90
H
, 98
H
, ..., F8
H
, FF
H
) are
bitaddressable.
The 52 special function registers (SFRs) in the standard and mapped SFR area include pointers
and registers that provide an interface between the CPU and the other on-chip peripherals. The
SFRs of the C505 are listed in Table 3 and Table 4. In Table 3 they are organized in groups which
refer to the functional blocks of the C505. The CAN-SFRs (applicable for the C505C and C505CA
only) are also included in Table 3. Table 4 illustrates the contents of the SFRs in numeric order of
their addresses. Table 5 list the CAN-SFRs in numeric order of their addresses.
Bit Function
RMAP Special function register map bit
RMAP = 0 : The access to the non-mapped (standard) special function register
area is enabled.
RMAP = 1 : The access to the mapped special function register area is enabled.
CSWO CAN Controller switch-off bit
CSWO = 0 : CAN Controller is enabled (default after reset).
CSWO = 1 : CAN Controller is switched off.
76543210
EALE RMAP CMOD
B1
H
SYSCON
Bit No. MSB LSB
CSWO
XMAP1
––
XMAP0
The functions of the shaded bits are not described here.
1)
1) This bit is only available in the C505CA.