HD64570 HITACHI [Hitachi Semiconductor], HD64570 Datasheet - Page 179

• Manufacturer Part Number: HD64570
• Description: Serial Communications Adaptor
• Manufacturer: HITACHI [Hitachi Semiconductor]

5.2.21
The TX/RX buffer register (TRB: TRBH, TRBL), located at the top of the 32-stage
transmit/receive buffer (TX/RX buffer), interfaces with the internal data bus. Although the TX
and RX buffers are physically different, this register is used for both reading receive data from the
RX register and writing transmit data to the TX buffer.
TRBH
TRBL
MSCI TX/RX Buffer Register (TRB: TRBH, TRBL)
Async
Byte sync
Bit sync HDLC
Read/Write
Initial value
X: Undefined
Async
Byte sync
Bit sync HDLC
Read/Write
Initial value
X: Undefined
(TRBH7)
(TRBL7)
TRB15
R/W
TRB7
R/W
Value written to, or read from, the transmit/receive buffer
Value written to, or read from, the transmit/receive buffer
X
X
7
7
(TRBH6)
(TRBL6)
TRB14
R/W
TRB6
R/W
X
6
6
X
(TRBH5)
(TRBL5)
TRB13
R/W
R/W
TRB5
X
X
5
5
(TRBH4)
(TRBL4)
TRB12
R/W
TRB4
R/W
X
X
4
4
(TRBH3)
(TRBL3)
TRB11
R/W
TRB3
R/W
X
X
3
3
Rev. 0, 07/98, page 163 of 453
(TRBH2)
(TRBL2)
TRB10
R/W
TRB2
R/W
X
X
2
2
(TRBH1)
(TRBL1)
TRB9
R/W
TRB1
R/W
X
X
1
1
(TRBH0
(TRBL0
TRB8
R/W
TRB0
R/W
X
X
0
0