UPD77111 NEC, UPD77111 Datasheet - Page 20

• Manufacturer Part Number: UPD77111
• Description: 16-BIT FIXED-POINT DIGITAL SIGNAL PROCESSORS
• Manufacturer: NEC

2. FUNCTION OUTLINE
2.1 Program Control Unit
of the DSP.
2.1.1 CPU control
branch instructions, are executed in one system clock.
2.1.2 Interrupt control
interface and host interface) are serviced. The interrupt of each interrupt source can be enabled or disabled.
Multiple interrupts are also supported.
2.1.3 Loop control task
multiple loops.
2.1.4 PC stack
2.1.5 PLL
clock to the DSP. The multiplication and division ratio are set as follows:
2.1.6 Instruction memory
rewritten by self boot (boot from the internal data ROM or external data space) or host boot (boot via host interface).
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This unit is used to execute instructions, and control branching, loops, interrupts, the clock, and the standby mode
A three-stage pipeline architecture is employed and almost all the instructions, except some instructions such as
Interrupt requests input from external pins (INT1 through INT4) or generated by the internal peripherals (serial
A loop function without any hardware overhead is provided. A loop stack with four levels is provided to support
A 15-level PC stack that stores the program counter supports multiple interrupts and subroutine calls.
A PLL is provided as a clock generator that can multiply or divide an external clock input to supply an operating
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Two standby modes are available for lowering the power consumption while the DSP is not in use.
• HALT mode : Set by execution of the HALT instruction. The current consumption drops to several mA. The
• STOP mode: Set by execution of the STOP instruction. The current consumption drops to several 10 A. The
Note If the WAKEUP function is activated by mask option
The capacity and type of the memory differ depending on the model of the DSP.
64 words of the instruction RAM are allocated to interrupt vectors.
A boot-up ROM that boots up the instruction RAM is provided, and the instruction RAM can be initialized or
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PD77110: A multiple of 1 to 8 is specified by an external pin (division ratio is fixed).
PD77111 and 77112: A multiple of 1 to 16 or a division ratio of 1/1 to 1/16 can be set by a mask option.
PD77110: 35.5K-word RAM
PD77111, 77112: 1K-word RAM and 31.75K-word ROM
normal operation mode is recovered by an interrupt or hardware reset.
normal operation mode is recovered by hardware reset or WAKEUP pin
Data Sheet U12801EJ4V0DS00
PD77110, 77111, 77112
Note
.