NEC Mu754202, Техническое описание

Страница: 17 / 66

17
µ
PD754202, 754202(A)
6. PERIPHERAL HARDWARE FUNCTION
6.1 Digital I/O Port
The following two types of I/O ports are provided.
• CMOS Input (PORT7) : 4
• CMOS Input/Output (PORT3, 6, 8) : 9
Total 13
Table 6-1. Types and Features of Digital Ports
Port Name Function Operation and Features Remarks
PORT3 4-bit I/O Can be set to input or output mode bit-wise. Also used for PTO0 to PTO2
pins.
PORT6 Also used for INT0 pin.
PORT7 4-bit input 4-bit input only port Also used for KR4 to KR7 pins.
On-chip pull-up resistor can be specified by mask
option bit-wise.
PORT8 1-bit I/O Can be set to input or output mode bit-wise. –
6.2 Clock Generator
The clock generator provides the clock signals to the CPU and peripheral hardware. Its configuration is shown
in Figure 6-1.
The operation of the clock generator is set with the processor clock control register (PCC). The instruction
execution time can be changed as follows.
• 0.95, 1.91, 3.81, 15.3
µ
s (system clock operating at 4.19 MHz)
• 0.67, 1.33, 2.67, 10.7
µ
s (system clock operating at 6.0 MHz)