SH7052 datasheet(397/919 Pages) RENESAS

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10.5.4

8-Bit or 16-Bit Accessible Registers

The timer control registers (TCR1A, TCR1B, TCR2A, TCR2B, TCR6A, TCR6B, TCR7A,

TCR7B), timer I/O control registers (TIOR1A to TIOR1D, TIOR2A to TIOR2D, TIOR3A,

TIOR3B, TIOR4A, TIOR4B, TIOR5A, TIOR5B), and the timer start register (TSTR1, TSTR2,

TSTR3) are 8-bit registers. These registers are connected to the upper 8 bits or lower 8 bits of the

internal 16-bit data bus, and can be read or written a byte at a time.

In addition, a pair of 8-bit registers for which only the least significant bit of the address is

different, such as timer I/O control register 1A (TIOR1A) and timer I/O control register 1B

(TIOR1B), can be read or written in combination a word at a time.

Figures 10.49 and 10.50 show the operation when performing individual byte read or write

accesses to TIOR1A and TIOR1B. Figure 10.51 shows the operation when performing a word

read or write access to TIOR1A and TIOR1B simultaneously.

CPU

Internal data bus

Only upper 8 bits used

TIOR1B

TIOR1A

Module data bus

Bus

interface

Figure 10.49 Byte Read/Write Access to TIOR1B

CPU

Internal data bus

Only lower 8 bits used

TIOR1B

TIOR1A

Module data bus

Bus

interface

Figure 10.50 Byte Read/Write Access to TIOR1A

CPU

Internal data bus

TIOR1B

TIOR1A

Module data bus

Bus

interface

Figure 10.51 Word Read/Write Access to TIOR1A and TIOR1B

SH7052 Datasheet(PDF) 397 Page - Renesas Technology Corp