
CHAPTER 1 INTRODUCTION
Preliminary User’s Manual U16541EJ1V0UM
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(10) Watchdog timer 2
A watchdog timer is provided on chip to detect inadvertent program loops, system abnormalities, etc.
Either the Ring-OSC, the main clock, or the subclock can be selected as the source clock.
Watchdog timer 2 generates a non-maskable interrupt request signal (INTWDT2) or a system reset signal
(WDT2RES) after an overflow occurs.
(11) Serial interface (SIO)
The V850ES/SG2 includes three kinds of serial interfaces: asynchronous serial interface A (UARTA), 3-wire
variable-length serial interface B (CSIB), and an I
2C bus interface (I2C). These interfaces which can use up to
seven channels at the same time. One of these channels is switchable between UARTA and CSIB, another
two channels are switchable between UARTA and I
2C, and another one is switchable between CSIB and I2C.
In the case of UARTA, data is transferred via the TXDA0 to TXDA2 pins and RXDA0 to RXDA2 pins.
In the case of CSIB, data is transferred via the SOB0 to SOB4 pins, SIB0 to SIB4 pins, and SCKB0 to
SCKB4 pins.
In the case of I
2C, data is transferred via the SDA00 to SDA02 and SCL00 to SCL02 pins.
A dedicated baud rate generator is provided on chip for UARTA.
(12) IEBus controller
The IEBus controller is a small-scale digital data transmission system for transferring data between units.
The IEBus controller is provided only in the IEBus controller version (see Table 1-1).
(13) CAN controller
The CAN controller is a small-scale digital data transmission system for transferring data between units.
The CAN controller is provided only in the CAN controller version (see Table 1-1).
(14) A/D converter
This high-speed, high-resolution 10-bit A/D converter includes 12 analog input pins. Conversion is performed
using the successive approximation method.
(15) D/A converter
A two-channel, 8-bit-resolution D/A converter that uses the R-2R ladder method is provided on chip.
(16) DMA controller
A 4-channel DMA controller is provided on chip. This controller transfers data between the internal RAM and
on-chip peripheral I/O devices in response to interrupt requests sent by on-chip peripheral I/O.
(17) ROM correction
A ROM correction function that replaces part of a program in the mask ROM with a program in the internal
RAM is provided. Up to four correction addresses can be specified.
(18) Key interrupt function
A key interrupt request signal (INTKR) can be generated by inputting a falling edge to key input pins (8
channels).