D12320VF25V Datasheet, PDF (374/1146 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 9 16-Bit Timer Pulse Unit (TPU)
9.3 Interface to Bus Master
9.3.1 16-Bit Registers
TCNT and TGR are 16-bit registers. As the data bus to the bus master is 16 bits wide, these
registers can be read and written to in 16-bit units.
These registers cannot be read or written to in 8-bit units; 16-bit access must always be used.
An example of 16-bit register access operation is shown in figure 9.2.
Internal data bus
H
Bus
master ^L
Bus interface
Module
data bus
TCNTH
TCNTL
Figure 9.2 16-Bit Register Access Operation [Bus Master ↔ TCNT (16 Bits)]
9.3.2 8-Bit Registers
Registers other than TCNT and TGR are 8-bit. As the data bus to the CPU is 16 bits wide, these
registers can be read and written to in 16-bit units. They can also be read and written to in 8-bit
units.
Rev.7.00 Feb. 14, 2007 page 340 of 1108
REJ09B0089-0700