HFC-SUSB Cologne Chip AG, HFC-SUSB Datasheet - Page 8

• Manufacturer Part Number: HFC-SUSB
• Description: Isdn S/t HDLC Basic Rate Controller
• Manufacturer: Cologne Chip AG

863 C EC2
1.2
The HFC-S USB has 2 different bus modes, which can be selected like shown in the table below.
Depending on the selected mode the function of several pins is different (see: Pin description).
Table 1: Mode selection
1.2.1 Passive USB Mode (Mode 1)
The Passive USB Mode (mode 1) is used for passive USB terminal adapters. An external processor is not
required in this mode.
The microprocessor interface is disabled in this mode and can be used as auxiliary port instead (e.g. for
LEDs).
1.2.2 Active USB Mode (Mode 2)
In Active USB Mode (mode 2) the USB interface and ISDN interface of the HFC-S USB are controlled
by an external microprocessor.
The microprocessor interface is enabled. The auxiliary port can not be used in this mode.
The data bus is PORT_D[7:0].
A0 (pin 47) is the address bus. The higher address (A0 = '1') is used for register selection and the lower
address (A0 = '0') is used for data read/write.
( _V ("
MODE
GND
VDD
Mode description
Passive USB Mode (mode 1)
Active USB Mode (mode 2)
Selected mode
Cologne
Chip
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