Datasheet

Section 14 Timer Z
Rev. 3.00 Mar. 15, 2006 Page 236 of 526
REJ09B0060-0300
14.3.14 Interface with CPU
1. 16-bit register
TCNT and GR are 16-bit registers. Reading/writing in a 16-bit unit is enabled but disabled in
an 8-bit unit since the data bus with the CPU is 16-bit width. These registers must always be
accessed in a 16-bit unit. Figure 14.5 shows an example of accessing the 16-bit registers.
H
Internal data bus
Bus interface
Module data bus
C
P
U
L
TCNTLTCNTH
Figure 14.5 Accessing Operation of 16-Bit Register (between CPU and TCNT (16 bits))
2. 8-bit register
Registers other than TCNT and GR are 8-bit registers that are connected internally with the
CPU in an 8-bit width. Figure 14.6 shows an example of accessing the 8-bit registers.
TSTR
H
Internal data bus
Bus interface
Module data bus
C
P
U
L
Figure 14.6 Accessing Operation of 8-Bit Register (between CPU and TSTR (8 bits))