IBM EM78P312N Benutzerhandbuch
EM78P312N
8-Bit Microcontroller
28
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Product Specification (V1.0) 10.03.2006
(This specification is subject to change without further notice)
5.7 UART (Universal Asynchronous Receiver/Transmitter)
Registers for UART Circuit
R_BANK Address Name Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
URTD8 UMODE1 UMODE0 BRATE2 BRATE1 BRATE0 UTBE
TXE
Bank 2
0X05
URC1
R/W R/W R/W R/W R/W R/W R R/W
0 0
SBIM1 SBIM0
UINVEN
0 0 0
Bank 2
0X06
URC2
-- --
R/W R/W R/W
-- -- --
URRD8
EVEN PRE
PRERR OVERR FMERR
URBF RXE
Bank 2
0X07
URS
R/W R/W R/W R/W R/W R/W R R/W
URRD7 URRD6 URRD5 URRD4
URRD3
URRD2 URRD1 URRD0
Bank 2
0X08
URRD
R R R R R R R R
URTD 7 URTD 6
URTD 5
URTD 4 URTD 3 URTD 2 URTD 1 URTD0
Bank 2
0X09
URTD
W W W W W W W W
0
UERRIF
RBFF TBEF
TBIF
EXIF1 0 TCIF0
Bank 0
0x0F
ISFR2
--
R/W R/W R/W
R/W
R/W -- R/W
0
UERRIE
URIE UTIE
TBIE EXIE1 0 TCIE0
SFR 0x0F
IMR2
--
R/W R/W R/W
R/W
R/W -- R/W
Baud rate
generator
Sele
cto
r
r
TC4
RX Control
TX Control
Interrupt
Control
RX shift register
URRD
URTD
URRD8
RX
TX
Parity control
Error flag
Data Bus
URTD8
RXE
TXE
UINVEN
UINVEN
Fsystem
Fig. 5-10 Function Block Diagram
In Universal Asynchronous Receiver Transmitter (UART), each transmitted or received
character is individually synchronized by framing it with a start bit and stop bit.
character is individually synchronized by framing it with a start bit and stop bit.
Full duplex data transfer is possible since the UART has independent transmit and
receive sections. Double buffering for both sections allows the UART to be
programmed for continuous data transfer.
receive sections. Double buffering for both sections allows the UART to be
programmed for continuous data transfer.