HD6433044 Hitachi Semiconductor, HD6433044 Datasheet - Page 343

• Manufacturer Part Number: HD6433044
• Description: (HD64 Series) Hitachi Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

10.3 CPU Interface
10.3.1 16-Bit Accessible Registers
The timer counters (TCNTs), general registers A and B (GRAs and GRBs), and buffer registers A
and B (BRAs and BRBs) are 16-bit registers, and are linked to the CPU by an internal 16-bit data
bus. These registers can be written or read a word at a time, or a byte at a time.
Figures 10-6 and 10-7 show examples of word access to a timer counter (TCNT). Figures 10-8,
10-9, 10-10, and 10-11 show examples of byte access to TCNTH and TCNTL.
CPU
CPU
On-chip data bus
On-chip data bus
H
L
Figure 10-6 Access to Timer Counter (CPU Writes to TCNT, Word)
H
L
Figure 10-7 Access to Timer Counter (CPU Reads TCNT, Word)
Bus interface
Bus interface
331
TCNTH
TCNTH
TCNTL
TCNTL
H
L
H
L
Module
data bus
Module
data bus