ISP1130DL Philips Semiconductors, ISP1130DL Datasheet - Page 8

• Manufacturer Part Number: ISP1130DL
• Description: Universal Serial Bus compound hub with integrated keyboard controller
• Manufacturer: Philips Semiconductors

Philips Semiconductors
9397 750 06895
Objective specification
6.1 80C51 microcontroller
6.2 Analog transceivers
6.3 Philips Serial Interface Engine (SIE)
6.4 Hub repeater
6.5 End-of-frame timers
6.6 General and individual port controller
An integrated 80C51 microcontroller serves as a keyboard controller. It has 8 kbytes
of mask ROM and 256 bytes of RAM. The I/O ports have been configured as an
8
indicators (Caps Lock, Num Lock and Scroll Lock). Interfacing to the USB hub is done
via 3 registers (command, data, status), which are accessible via the external data
memory address space (MOVX instruction).
The keyboard firmware resides in the ROM and enumerates the embedded function
as ‘HID compatible keyboard device’ during hub initialization.
The microcontroller runs on a 12 MHz clock, derived from the PLL oscillator. A
watchdog timer resets the microcontroller in case of a software hang-up.
The integrated transceivers interface directly to the USB cables through external
termination resistors. They are capable of transmitting and receiving serial data at
both ‘full-speed’ (12 Mbit/s) and ‘low-speed’ (1.5 Mbit/s) data rates. The slew rates
are adjusted according to the speed of the device connected and lie within the range
mentioned in the USB Specification Rev. 1.1 .
The Philips SIE implements the full USB protocol layer. It is completely hardwired for
speed and needs no firmware intervention. The functions of this block include:
synchronization pattern recognition, parallel/serial conversion, bit (de-)stuffing, CRC
checking/generation, Packet IDentifier (PID) verification/generation, address
recognition, handshake evaluation/generation.
The hub repeater is responsible for managing connectivity on a ‘per packet’ basis. It
implements ‘packet signalling’ and ‘resume’ connectivity. Low-speed devices can be
connected to downstream ports. If a low-speed device is detected the repeater will
not propagate upstream packets to the corresponding port, unless they are preceded
by a PREAMBLE PID.
This block contains the specified EOF1 and EOF2 timers which are used to detect
‘loss-of-activity’ and ‘babble’ error conditions in the hub repeater. The timers also
maintain the low-speed keep-alive strobe which is sent at the beginning of a frame.
The general and individual port controllers together provide status and control of
individual downstream ports. Any port status change will be reported to the host via
the hub status change (interrupt) endpoint.
18 line scan matrix. Three LED control outputs are available for keyboard status
Rev. 01 — 23 March 2000
USB compound hub with keyboard controller
© Philips Electronics N.V. 2000. All rights reserved.
ISP1130
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