UPD78361A Datasheet, PDF (26/88 Pages) NEC – 16/8-BIT SINGLE-CHIP MICROCONTROLLER

µPD78361A, 78362A
3. FUNCTIONAL BLOCKS
3.1 EXECUTION UNIT (EXU)
EXU controls address computation, arithmetic and logical operations, and data transfer through microprogram.
EXU has an internal main RAM. This RAM can be accessed by instructions faster than the peripheral RAM.
3.2 BUS CONTROL UNIT (BCU)
BCU starts necessary bus cycles according to the physical address obtained by the execution unit (EXU).If
EXU does not request start of the bus cycle, an address is generated to prefetch an instruction. The prefetched
op code is stored in an instruction queue.
3.3 ROM/RAM
Internal ROM and RAM capacities differ depending on the product.
The µPD78361A has a 32K-byte ROM and a 1792-byte peripheral RAM.
The µPD78362A has a 24K-byte ROM and a 512-byte peripheral RAM.
3.4 PORT FUNCTIONS
The µPD78362A is provided with the ports shown in Figure 3-1 for various control operations.
The functions of each port are listed in Table 3-1. These ports function not only as digital ports but also as
input/output lines of the internal hardware.
Figure 3-1. Port Configuration
P00
Port 0
P07
P20
Port 2
P25
P30
Port 3
P34
Port 4
8
P40-P47
P50
Port 5
P57
P70-P77
8
Port 7
P80
Port 8
P85
P90
Port 9
P92
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