Cypress enCoRe CY7C602xx User Manual
Page 24
CY7C601xx, CY7C602xx
Document 38-16016 Rev. *E
Page 24 of 68
Read/Write
–
–
R/W
R/W
R/W
R/W
R/W
R/W
Default
0
0
0
0
0
0
0
0
Bit [7:6]: Reserved
Bit 5: No Buzz
During sleep (the Sleep bit is set in the CPU_SCR Register—
), the LVD and POR detection circuit is turned on periodically
to detect any POR and LVD events on the V
CC
pin (the Sleep Duty Cycle bits in the ECO_TR are used to control the duty
cycle—
). To facilitate the detection of POR and LVD events, the No Buzz bit is used to continuously enable the LVD and
POR detection circuit during sleep. This results in a faster response to an LVD or POR event during sleep at the expense of a slightly
higher than average sleep current. Obtaining the absolute lowest power usage in sleep mode requires the No Buzz bit be clear.
0 = The LVD and POR detection circuit is turned on periodically as configured in the Sleep Duty Cycle.
1 = The Sleep Duty Cycle value is overridden. The LVD and POR detection circuit is always enabled.
Note The periodic Sleep Duty Cycle enabling is independent with the sleep interval shown in the Sleep [1:0] bits below.
Bit [4:3]: Sleep Timer [1:0]
Note Sleep intervals are approximate.
Bit [2:0]: CPU Speed [2:0]
The enCoRe II LV operates over a range of CPU clock speeds. The reset value for the CPU Speed bits is zero; therefore, the default
CPU speed is 3 MHz.
Note This register exists in the second bank of IO space. This requires setting the XIO bit in the CPU flags register.
Table 12-3. OSC Control 0 (OSC_CR0) [0x1E0] [R/W] (continued)
Sleep Timer
[1:0]
Sleep Timer Clock
Frequency (Nominal)
Sleep Period
(Nominal)
Watchdog Period
(Nominal)
00
512 Hz
1.95 ms
6 ms
01
64 Hz
15.6 ms
47 ms
10
8 Hz
125 ms
375 ms
11
1 Hz
1 sec
3 sec
CPU Speed
[2:0]
CPU when Internal
Oscillator is selected
External Clock
000
3 MHz (Default)
Clock In/8
001
6 MHz
Clock In/4
010
12 MHz
Clock In/2
011
Reserved
Reserved
100
1.5 MHz
Clock In/16
101
750 KHz
Clock In/32
110
187 KHz
Clock In/128
111
Reserved
Reserved