M306H7MG-XXXFP Datasheet, PDF (201/329 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with DATA ACQUISITION CONTROLLER

M306H7MG-XXXFP/MC-XXXFP/FGFP
14. EXPANSION FUNCTION
For accessing to expansion register data, set accessing address (DA5 to DA0) (shown in Table 14.4) to expansion
register address control register (address 021616). Then write data (DD15 to DD0) to expansion register data
control register (address 021816). When end the data accessing, expansion register address control register
increments address automatically. Then, next address data writing is possible. After reset, the value of expansion
register become “0” all, except for the clock timer.
Expansion register access registers are shown in Figure 14.9, expansion register access block
diagram is shown in Figure 14.10, and expansion register bit compositions are shown in p202 to p239.
Expansion register address control register
b15
b8 b7 b6
b0
Symbol
DA
Address
021616
When reset
000016
Function
Specify accessing expansion register address
Setting possible value R W
0016 to 4516
Nothing is assigned.
When write, set to “0”.
When read, its content is indeterminate.
Expansion register address automatic increment
0:enable / 1:disable (Note2)
Nothing is assigned.
In an attempt to write to these bits, write “0”. The value, if read, turns out to
be indeterminated.
Note1 : When access to expansion register, must be set expansion register address
at first, then use expansion register data control register (021816).
Note2 : When bit 8 = “0” setting, expansion register data control register increments by
accessing expansion register data control register, so it is not necessary to
setting the next expansion register address. When bit 8 = “1” setting, the address
is fixed.
Expansion register data control register
b15
b8 b7
b0
Symbol
DD
Address
021816
When reset
000016
Function
Setting possible value R W
Write and read out the data of expansion register which is
specified by expansion register address control register
(address 021616)
000016 to FFFF16
Note : Data access must be 16-bit unit. 8-bit unit access is disable.
Figure 14.9 Expansion register access registers composition
Data bus (16-bit)
(address 021616) (DA8)
Expansion register address
control register (6) (DA5 to DA0)
Expansion register data control
register (16) (DD15 to DD0)
(address 021816)
Increment automatically
after data access
Expansion register
Figure 14.10 Expansion register access block diagram
Rev.2.10 Oct 25, 2006 Page 201 of 326
REJ03B0152-0210