UPD784907 Datasheet, PDF (57/98 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLER

µPD784907, 784908
9.5 Examples of Macro Service Applications
(1) Serial interface transmission
Transmit data storage buffer (memory)
Data n
Data n - 1
Data 2
Data 1
Internal bus
TxD
Transmit
shift register
TXS (SFR)
Transmit control
INTST
Each time macro service request (INTST) is generated, the next transmit data is transferred from memory to TXS.
When data n (last byte) has been transferred to TXS (that is, once the transmit data storage buffer becomes
empty), vectored interrupt request (INTST) is generated.
(2) Serial interface reception
Receive data storage buffer (memory)
Data n
Data n - 1
Data 2
Data 1
Internal bus
Receive buffer RXB (SFR)
RxD
Receive
shift register
Receive control
INTSR
Each time macro service request (INTSR) is generated, receive data is transferred from RXB to memory. When
data n (last byte) has been transferred to memory (that is, once the receive data storage buffer becomes full),
vectored interrupt request (INTSR) is generated.
Data Sheet U11680EJ2V0DS00
57