w83627sf Winbond Electronics Corp America, w83627sf Datasheet - Page 58

• Manufacturer Part Number: w83627sf
• Description: Winbond I/o
• Manufacturer: Winbond Electronics Corp America

4.2.3 Handshake Control Register (HCR) (Read/Write)
This register controls the pins of the UART used for handshaking peripherals such as modem, and
controls the diagnostic mode of the UART.
Bit 4: When this bit is set to a logical 1, the UART enters diagnostic mode by an internal loopback, as
Bit 3: The UART interrupt output is enabled by setting this bit to a logic 1. In the diagnostic mode this bit
Bit 2: This bit is used only in the diagnostic mode.
Bit 1: This bit controls the RTS output. The value of this bit is inverted and output to RTS .
Bit 0: This bit controls the DTR output. The value of this bit is inverted and output to DTR .
follows:
(1) SOUT is forced to logical 1, and SIN is isolated from the communication link instead of the
(2) Modem output pins are set to their inactive state.
(3) Modem input pins are isolated from the communication link and connect internally as DTR
is internally connected to the modem control input DCD .
connected to the modem control input RI .
TSR.
(bit 0 of HCR)
Aside from the above connections, the UART operates normally. This method allows the CPU
to test the UART in a convenient way.
RI and IRQ enable ( bit 3 of HCR)
7
0
0
6
DSR, RTS ( bit 1 of HCR)
5
0
4
3
2
DCD .
1
- 51 -
0
In the diagnostic mode this bit is internally
Data terminal ready (DTR)
Request to send (RTS)
Loopback RI input
IRQ enable
Internal loopback enable
CTS , Loopback RI input ( bit 2 of HCR)
Publication Release Date: Nov. 2000
PRELIMINARY
W83627SF
Revision 0.60