NEC switch - Manual (Page 27)

CHAPTER 1 GENERAL
User’s Manual U12978EJ3V0UD
27
1.7 Functions
Product
Item
µPD789800 µPD78F9801
Internal memory ROM Mask ROM
8 KB
Flash memory
16 KB
High-speed RAM 256 bytes
Minimum instruction execution time 0.33
µs/1.33 µs (at 6.0 MHz operation with system clock)
Instruction set • 16-bit operation
• Bit manipulation (set, reset, and test) etc.
I/O ports CMOS I/O 31
(Of the above COMS I/O ports, 18 ports can be switched to N-ch open-drain
I/O ports.)
Serial interface • USB (Universal Serial Bus) function: 1 channel
• Three-wired serial I/O mode: 1 channel
Timer • 8-bit timer: 1 channel
• 8-bit timer/event counter: 1 channel
• Watchdog timer: 1 channel
Regulator Incorporated (V REG = 3.3 ±0.3 V)
Maskable Internal: 9, external: 2 Vector interrupt
sources
Non-maskable Internal: 1
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 a flash memory is written)
Package 44-pin plastic LQFP (10 × 10)
An outline of the timer is shown below.
8-Bit Timer 00 8-Bit Timer/
Event Counter 01
Watchdog Timer
Interval timer 1 channel 1 channel 1 channel Note Operation mode
External event counter −−−− 1 channel −−−−
Timer outputs −−−− 1 output −−−−
Square-wave outputs −−−− 1 output −−−−
Capture −−−− −−−− −−−−
Function
Interrupt sources 1 1 2
Note The watchdog timer has watchdog timer and interval timer functions. However, use the watchdog timer by
selecting either the watchdog timer function or interval timer function.