NEC switch - CHAPTER 1 GENERAL; 1.1 Features; 1.3 Ordering Information

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.