NEC switch Network Card User Manual


 
User’s Manual U12978EJ3V0UD
21
CHAPTER 1 GENERAL
1.1 Features
On-chip USB functions
Implements a USB (Universal Serial Bus) by connecting to Hub and Host.
Transfer speed: 1.5 Mbps (at 6.0 MHz operation with system clock)
On-chip regulator
Controls the USB port voltage by using a bus power supply (VREG
= 3.3 ±0.3 V) dedicated to the USB
driver/receiver.
On-chip ROM and RAM
Internal ROM: 8 KB
Flash memory (for
µ
PD78F9801 only): 16 KB
Internal high-speed RAM: 256 bytes
Variable minimum instruction execution time: From high-speed (0.33
µ
s) to low speed (1.33
µ
s) with the system
clock operating at 6.0 MHz
31 I/O ports
Two serial interface channels
USB function
3-wire serial I/O mode
Three timers:
8-bit timer
8-bit timer/event counter
Watchdog timer
On-chip key return signal detector
12 vectored interrupt sources
Power supply voltage: V
DD
= 4.0 to 5.5 V
Operating ambient temperature: T
A
= –40 to +85°C (when the USB is not operating)
T
A
= 0 to +70°C (when the USB is operating)
T
A
= 10 to 40°C (when the flash memory is written)
1.2 Applications
USB keyboards, etc.
1.3 Ordering Information
Part Number Package Internal ROM
µ
PD789800GB-×××-8ES 44-pin plastic LQFP (10 × 10) Mask ROM
µ
PD78F9801GB-8ES 44-pin plastic LQFP (10 × 10) Flash memory
Remark ××× indicates ROM code suffix.