
453
17.4 Registers of the Bridge Circuit
Note:
Switching of the connection destination is valid only when the resource function of the
connection destination has been allowed. Be careful not to duplicate the port specification
for switching the connection destination between this register and the BRSR3 register.
Table 17.4-3 Bridge Circuit Selection Register 3 (BRSR3) Bit Functions
Bit name
Function
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Unused bits
The read value is undefined.
Writing has no effect on operation.
Bit 2
BU3:
Bridge circuit UART
selection 3
This bit specifies options for "P33/SCL2/UCK3, P34/SDA2/
UI3, and P35/UO3" whether they are connected to UART.
When "1" is written in this bit, UART is selected.
UCK3 (P33): Acts as UCK only when UART serial clock
output is allowed (SMC2:SCKE = 1).
UI3 (P34)
UO3 (P35): Acts as UO only when UART serial data
output is allowed (SMC2:TXOE = 1).
When "0" is written in this bit, the port function is selected.
Bit 1
BU2:
Bridge circuit UART
selection 2
This bit specifies options for "P42/SCL4/UCK2, P43/SDA4/
UI2, and P64/UO2" whether thy are connected to UART.
When "1" is written in this bit, UART is selected.
UCK2 (P42): Acts as UCK only when UART serial clock
output is allowed (SMC2:SCKE = 1).
UI2 (P43)
UO2 (P64): Acts as UO only when UART serial data
output is allowed (SMC2:TXOE = 1).
When "0" is written in this bit, the port function is selected.
Bit 0
BU1:
Bridge circuit UART
selection 1
This bit specifies options for "P40/SCL3/UCK1, P41/SDA3/
UI1, and P65/UO1" whether they are connected to UART.
When "1" is written in this bit, UART is selected.
UCK1 (P40): Acts as UCK only when UART serial clock
output is allowed (SMC2:SCKE = 1).
UI1 (P41)
UO1 (P65): Acts as UO only when UART serial data
output is allowed (SMC2:TXOE = 1).
When "0" is written in this bit, the port function is selected.