CobraNet Hardware User’s Manual
Pinout and Signal Descriptions
4.2 Signal Descriptions
4.2.1 Host Port Signals
The host port is used to manage and monitor the CobraNet interface. Electrical operation
and protocol is detailed in the "Host Management Interface (HMI)" on page 23 of this
Manual.
The host port can operate in two modes in order to accomodate Motorola® or Intel® style
interfaces. The default mode is Motorola. Intel mode is set via a firmware modification.
Table 2-1: Host Port Signals
CM-2
Pin #
CS1810xx/
CS4961xx Pin #
Signal
Description Direction
Notes
111, 112, 114,
115, 117, 118,
102, 121
J1:A19,
A[17:11]
HDATA[7:0]
Host Data
In/Out
Host port data.
J1:A20,
A[10:8]
HADDR[3:0] Host Address
In
In
105, 106, 109,110 Host port address.
Host
HRW
J1:A4
107
Host port transfer direction (Motorola mode).
Direction
HRD
HREQ
HACK
HDS
Host Read
Host Request
Host Alert
Host Strobe
Host Write
Host Enable
Select
In
Out
Out
In
J1:A4
J1:A6
J1:A3
J1:A5
J1:A5
J1:A7
J1:A7
107
140
102
103
103
104
104
Host Read (Intel mode).
Host port data request.
Host port interrupt request.
Host port strobe (Motorola mode).
Host Write (Intel mode).
Host Port Enable.
HWR
HEN
In
In
HCS
In
Select (Intel mode).
4.2.2 Asynchronous Serial Port (UART Bridge) Signals
Level-shifting drive circuits are typically required between these signals and any external
connections.
CM-2
Pin #
CS1810xx/
CS4961xx Pin #
Signal
Description
Direction
Notes
Asynchronous Serial
Receive Data
UART_RXD
UART_TXD
In
J1:A1
J1:B1
J1:A2
26
25
23
Pull-up to VCC if unused.
Asynchronous Serial
Transmit Data
Out
Out
Enable transmit (active high) drive for
two wire multi-drop interface.
UART_TX_OE
Transmit Drive Enable
12
©Copyright 2005 Cirrus Logic, Inc.
DS651UM23
Version 2.3
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