upd78f0114m6gb-8es Renesas Electronics Corporation., upd78f0114m6gb-8es Datasheet - Page 121

• Manufacturer Part Number: upd78f0114m6gb-8es
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

5.7 Time Required for CPU Clock Switchover
register (PCC).
the pre-switchover clock for several instructions (see Table 5-6).
ascertained using bit 5 (CLS) of the PCC register.
CSS PCC2 PCC1 PCC0
Set Value Before
0
1
The CPU clock can be switched using bits 0 to 2 (PCC0 to PCC2) and bit 4 (CSS) of the processor clock control
The actual switchover operation is not performed immediately after rewriting to the PCC; operation continues on
Whether the system is operating on the X1 input clock (or Ring-OSC clock) or the subsystem clock can be
Cautions 1. Selection of the CPU clock cycle division factor (PCC0 to PCC2) and switchover from the X1
Remarks 1. The maximum time is the number of clocks of the pre-switchover CPU clock.
Switchover
0
0
0
0
1
×
0
0
1
1
0
×
2. Figures in parentheses apply to operation with f
0
1
0
1
0
×
2. Setting the following values is prohibited when the CPU operates on the Ring-OSC clock.
input clock to the subsystem clock (changing CSS from 0 to 1) should not be set
simultaneously.
Simultaneous setting is possible, however, for selection of the CPU clock cycle division
factor (PCC0 to PCC2) and switchover from the subsystem clock to the X1 input clock
(changing CSS from 1 to 0).
• CSS, PCC2, PCC1, PCC0 = 0, 0, 0, 1 (settable only for standard products and (A) grade
• CSS, PCC2, PCC1, PCC0 = 0, 0, 1, 0
• CSS, PCC2, PCC1, PCC0 = 0, 0, 1, 1
• CSS, PCC2, PCC1, PCC0 = 0, 1, 0, 0
CSS PCC2 PCC1 PCC0 CSS PCC2 PCC1 PCC0 CSS PCC2 PCC1 PCC0 CSS PCC2 PCC1 PCC0 CSS PCC2 PCC1 PCC0 CSS PCC2 PCC1 PCC0
0
products)
8 clocks
4 clocks
2 clocks
1 clock
1 clock
0
Table 5-6. Maximum Time Required for CPU Clock Switchover
0
0
0
16 clocks
4 clocks
2 clocks
1 clock
1 clock
0
CHAPTER 5 CLOCK GENERATOR
0
User’s Manual U16227EJ3V0UD
1
0
16 clocks
Set Value After Switchover
8 clocks
2 clocks
1 clock
1 clock
0
1
XP
0
= 12 MHz and f
0
16 clocks
8 clocks
4 clocks
1 clock
1 clock
0
1
1
XT
= 32.768 kHz.
0
16 clocks
8 clocks
4 clocks
2 clocks
1 clock
1
0
0
1
f
f
f
f
XP
f
(367 clocks)
XP
(184 clocks)
XP
XP
XP
(92 clocks)
(46 clocks)
(23 clocks)
/16f
/2f
/4f
/8f
/f
×
XT
XT
XT
XT
XT
clocks
clocks
clocks
clocks
clocks
×
121
×