h8s-2635 Renesas Electronics Corporation., h8s-2635 Datasheet - Page 246

• Manufacturer Part Number: h8s-2635
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 7 Bus Controller
7.7
Write Data Buffer Function
The chip has a write data buffer function in the external data bus. Using this function enables the
write data buffer to be accessed in parallel. The write data buffer function is made available by
setting the WDBE bit in BCRL to 1.
Figure 7-18 shows an example of the timing when the write data buffer function is used. When
this function is used, if an external write continues for 2 states or longer, and there is an internal
access next, only an external write is executed in the first state, but from the next state onward an
internal access (on-chip memory or internal I/O register read/write) is executed in parallel with the
external write rather than waiting until it ends.
B
HWR LWR
Figure 7-18 Example of Timing when Write Data Buffer Function Is Used
Rev. 6.00 Feb 22, 2005 page 186 of 1484
REJ09B0103-0600