71M6543F/H and 71M6543G/GH Data Sheet
Table 66: Clear Events for WAKE flags
Flag
Wake on:
Timer expiration
Clear Events
WAKE falls
WAKE falls
WAKE falls
WAKE falls
WAKE falls
WF_TMR
WF_PB
PB pin high level
WF_RX
Either edge RX pin
SEGDIO4 rising edge
SEGDIO52 high level
WF_DIO4
WF_DIO52
If OPT_RXDIS = 1 (I/O RAM 0x2457[2]),
wake on SEGDIO55 high
If OPT_RXDIS = 0
WF_DIO55
WAKE falls
wake on either edge of OPT_RX
RESET pin driven high
WAKE falls, WF_CSTART, WF_RSTBIT,
WF_OVF, WF_BADVDD
WF_RST
RESET bit is set (I/O RAM 0x2200[3])
WAKE falls, WF_CSTART, WF_OVF,
WF_BADVDD, WF_RST
WF_RSTBIT
E_RST pin driven high and the ICE
interface must be enabled by driving the
ICE_E pin high.
WAKE falls, WF_CSTART, WF_RST,
WF_OVF, WF_RSTBIT
WF_ERST
WF_OVF
Watchdog (WD) reset
WAKE falls, WF_CSTART, WF_RSTBIT,
WF_BADVDD, WF_RST
Cold-start (i.e., after the application of
first power)
WAKE falls, WF_RSTBIT, WF_OVF,
WF_BADVDD, WF_RST
WF_CSTART
Note:
“WAKE falls” implies that the internal WAKE signal has been reset, which happens automatically upon
entry into LCD mode or SLEEP mode (i.e., when the MPU sets the LCD_ONLY bit (I/O RAM 0x28B2[6]) or
the SLEEP (I/O RAM 0x28B2[7]) bit). When the internal WAKE signal resets, all wake flags are reset. Since
the various wake flags are automatically reset when WAKE falls, it is not necessary for the MPU to reset
these flags before entering LCD mode or SLEEP mode. Also, other wake events can cause the wake flag
to reset, as indicated above (e.g., the WF_RST flag can also be reset by any of the following flags setting:
WF_CSTART, WS_RSTBIT, WF_OVF, WF_BADVDD)
3.4.2 Wake on Timer
If the part is in SLP or LCD mode, it can be awakened by the Wake Timer. Until this timer times out, the
MPU is in reset due to the internal WAKE signal being low. When the Wake Timer times out, WAKE rises
and within three CK32 cycles, the MPU begins to execute. The MPU can determine that the timer woke it
by checking the WF_TMR (I/O RAM 0x28B1[2]) wake flag.
The Wake Timer begins timing when the part enters LCD or SLP mode. Its duration is controlled by the
WAKE_TMR[7:0] register (I/O RAM 0x2880). The timer duration is WAKE_TMR[7:0] +1 seconds.
The Wake Timer is armed by setting WAKE_ARM = 1 (I/O RAM 0x28B2[5]). It must be armed at least
three RTC cycles before either SLP or LCD modes are initiated. Setting WAKE_ARM presets the timer
with the value in WAKE_TMR and readies the timer to start when the MPU writes to the SLEEP (I/O RAM
0x28B2[7]) or LCD_ONLY (I/O RAM 0x28B2[6]) bits. The timer is neither reset nor disarmed when the
MPU wakes-up. Thus, once armed and set, the MPU continues to be awakened WAKE_TMR[7:0]
seconds after it requests SLP mode or LCD mode (i.e., once written, the WAKE_TMR[7:0] register holds
its value and does not have to be re-written each time the MPU enters SLP or LCD mode. Also, since
WAKE_TMR[7:0] is non-volatile, it also holds its value through resets and power failures).
3.5
Data Flow and MPU/CE Communication
The data flow between the Compute Engine (CE) and the MPU is shown in Figure 26. In a typical application,
the 32-bit CE sequentially processes the samples from the ADC inputs, performing calculations to measure
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