UPD784218 Datasheet, PDF (50/92 Pages) NEC – 16-/8-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784218, 784218Y
9.5 Application Example of Macro Service
(1) Serial interface transmission
Transmit data storage buffer (memory)
Data n
Data n – 1
Data 2
Data 1
Internal bus
TxD1, TxD2
Transmit shift register TXS1, TXS2 (SFR)
Transmit control
INTST1, INTST2
Each time macro service requests INTST1 and INTST2 are generated, the next transmit data is transferred from
memory to TXS1 and TXS2. When data n (last byte) has been transferred to TXS1 and TXS2 (when the transmit
data storage buffer has become empty), vectored interrupt requests INTST1 and INTST2 are generated.
(2) Serial interface reception
Receive data storage buffer (memory)
Data n
Data n – 1
Data 2
Data 1
Internal bus
RxD1, RxD2
Receive buffer register RXB1, RXB2 (SFR)
Receive shift register
Reception control
INTSR1, INTSR2
Each time macro service requests INTSR1 and INTSR2 are generated, the receive data is transferred from RXB1
and RXB2 to memory. When data n (last byte) has been transferred to memory (when the receive data storage
buffer has become full), vectored interrupt requests INTSR1 and INTSR2 are generated.
50
Data Sheet U12304EJ2V0DS00