NEC switch - Manual (Page 21)

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 (V
REG
= 3.3 ±0.3 V) dedicated to the USB
driver/receiver.
• On-chip ROM and RAM
• Internal ROM: 8 KB
Flash memory (for
µPD78F9801 only): 16 KB
• Internal high-speed RAM:
256 bytes
• Variable minimum instruction execution time: From high-speed (0.33 µs) to low speed (1.33 µs) 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
µPD789800GB-×××-8ES
44-pin plastic LQFP (10
× 10)
Mask ROM
µPD78F9801GB-8ES
44-pin plastic LQFP (10
× 10)
Flash memory
Remark ××× indicates ROM code suffix.