HD64F2638F20J Datasheet, PDF (397/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
Section 10 16-Bit Timer Pulse Unit (TPU)
10.3 Interface to Bus Master
10.3.1 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 10-2.
Internal data bus
H
Bus
master ^L
Bus interface
Module
data bus
TCNTH
TCNTL
Figure 10-2 16-Bit Register Access Operation [Bus Master ↔ TCNT (16 Bits)]
10.3.2 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.
REJ09B0103-0800 Rev. 8.00
May 28, 2010
Page 347 of 1458