HFC-4S Cologne Chip AG, HFC-4S Datasheet - Page 217

• Manufacturer Part Number: HFC-4S
• Description: Isdn HDLC Fifo Controller With 8 (4) Integrated S/t Interfaces
• Manufacturer: Cologne Chip AG

11.2 Various mode selections
The host-to-auxiliary bridge can be configured into various modes which define the behavior of the
bridge. The overview of these modes is illustrated in Figure 11.1 and will be described in the follow-
ing sections.
11.2.1 Driver mode
The behavior of the data bus of the auxiliary bridge can be modified by V_BRG_MD of the register
R_BRG_PCM_CFG. A ’0’ defines that the bus BRG_D0 . . . BRG_D7 is tristated when no bridge
access is performed and a ’1’ defines that the bus is only tristated when a read access is performed.
11.2.2 Control mode
The register R_BRG_MD defines for each chip select the style of the access.
The bit value ’0’ executes an access to the external device in Siemens/Intel style. Alternatively an
access in Motorola style can be selected with ’1’.
11.2.3 Access mode
The access mode is controlled by the two bit M0 and M1. A normal chip access is done with M[1..0]
= ’00’.
The CIP must be written with one 16 bit access to use the auxiliary interface.
March 2003 (rev. A)
HFC-4S
HFC-8S
Host
Host mode
/IOR
/DS
Figure 11.1: Points of contact of the various bridge modes
0
0
0
1
/IOW
R/
1
0
1
0
Ï
/CS
Table 11.3: Control mode
0
0
0
0
Auxiliary interface
HFC-4S / HFC-8S
ALE
Data Sheet
1
1
0
0
Operation
read data
write data
read data
write data
Access mode
Siemens/Intel
Siemens/Intel
Access style
Motorola
Motorola
chip select
address
control
data
Driver mode
Control mode
Cologne
Chip
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external
devices