Rev. 1.10
86
October 23, 2020
Rev. 1.10
87
October 23, 2020
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
BC66F5652
2.4GHz RF Transceiver A/D Flash MCU
Pin-shared Function Selection Registers
The limited number of supplied pins in a package can impose restrictions on the amount of functions
a certain device can contain. However by allowing the same pins to share several different functions
and providing a means of function selection, a wide range of different functions can be incorporated
into even relatively small package sizes. The device includes Port “x” output function Selection
register “n”, labeled as PxSn, and Input Function Selection register “n”, labeled as IFS, which can
select the desired functions of the multi-function pin-shared pins.
The most important point to note is to make sure that the desired pin-shared function is properly
selected and also deselected. For most pin-shared functions, to select the desired pin-shared function,
the pin-shared function should first be correctly selected using the corresponding pin-shared control
register. After that the corresponding peripheral functional setting should be configured and then the
peripheral function can be enabled. However, a special point must be noted for some digital input
pins, such as INTn, xTCKn, xTPI, etc, which share the same pin-shared control configuration with
their corresponding general purpose I/O functions when setting the relevant pin-shared control bit
fields. To select these pin functions, in addition to the necessary pin-shared control and peripheral
functional setup aforementioned, they must also be setup as an input by setting the corresponding bit
in the I/O port control register. To correctly deselect the pin-shared function, the peripheral function
should first be disabled and then the corresponding pin-shared function control register can be
modified to select other pin-shared functions.
Register
Name
Bit
7
6
5
4
3
2
1
0
PAS0
PAS07 PAS06 PAS05
PAS04
PAS03
PAS02
PAS01
PAS00
PAS1
PAS17 PAS16 PAS15
PAS14
PAS13
PAS12
PAS11
PAS10
PBS0
PBS07 PBS06 PBS05
PBS04
PBS03
PBS02
PBS01
PBS00
PBS1
—
—
PBS15
PBS14
PBS13
PBS12
PBS11
PBS10
PCS0
D7
D6
PCS05 PCS04
PCS03
PCS02
PCS01
PCS00
PDS0
PDS07 PDS06 PDS05 PDS04
PDS03
PDS02
PDS01
PDS00
IFS
—
—
INT1PS INT0PS SDI_SDAPS SCK_SCLPS SCSBPS RXPS
Pin-shared Function Selection Register List
• PAS0 Register
Bit
7
6
5
4
3
2
1
0
Name
PAS07
PAS06
PAS05
PAS04
PAS03
PAS02
PAS01
PAS00
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
POR
0
0
0
0
0
0
0
0
Bit 7~6
PAS07~PAS06
: PA3 Pin-Shared Function Selection
00: PA3
01: SDI/SDA
10: CX
11: SCOM3/SSEG3
Bit 5~4
PAS05~PAS04
: PA2 Pin-Shared Function Selection
00: PA2/INT1
01: PA2/INT1
10: PA2/INT1
11: SCOM2/SSEG2
Bit 3~2
PAS03~PAS02
: PA1 Pin-Shared Function Selection
00: PA1/INT0
01: PA1/INT0
10: SDO
11: SCOM1/SSEG1