UPD784907 Datasheet, PDF (52/98 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLER

µPD784907, 784908
• Hardware configuration and functions
The internal configuration of the IEBus consists mainly of the following six sections:
• CPU interface section
• Interrupt control section
• Internal register section
• Bit processing section
• Field processing section
• IEBus interface section
<CPU interface section>
Interfaces between the CPU (78K/IV) and the IEBus.
<Interrupt control section>
Passes interrupt request signals from the IEBus to the CPU.
<Internal register section>
Control register which stores the data in each field to control the IEBus.
<Bit processing section>
Generates and resolves the bit timing.
discriminator.
Mainly consists of the bit sequence ROM, 8-bit preset timer, and
<Field processing section>
Generates each field in the communication frame. Mainly consists of the field sequence ROM, 4-bit down counter,
and discriminator.
<IEBus interface section>
Interface section of the external driver/receiver. Mainly consists of the noise filter, shift register, conflict detector,
parity detector, parity generator, and ACK/NACK generator.
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Data Sheet U11680EJ2V0DS00