z86c9216vsc ZiLOG Semiconductor, z86c9216vsc Datasheet - Page 55

• Manufacturer Part Number: z86c9216vsc
• Description: Ir Microcontroller
• Manufacturer: ZiLOG Semiconductor

Zilog
SCLK/TCLK Divide-by-16 Select (D0). D0 of the SMR
controls a Divide-by-16 prescaler of SCLK/TCLK. The pur-
pose of this control is to selectively reduce device power
consumption during normal processor execution (SCLK
control) and/or HALT mode (where TCLK sources interrupt
logic). After Stop-Mode Recovery, this bit is set to a 0.
Stop-Mode Recovery Source (D2, D3, and D4). These
three bits of the SMR specify the wake up source of the
STOP recovery (Figure 39 and Table 5).
P33-P31 cannot wake up from stop mode if the input lines
are configured as analog input.
Note: Any Port 2 bit defined as an output will drive the cor-
responding input to the default state to allow the remaining
inputs to control the AND/OR function. Refer to SMR2 reg-
ister for other recover sources.
DS97LVO0900
D4
0
0
0
0
1
1
1
1
D3
Table 5. Stop-Mode Recovery Source
0
0
1
1
0
0
1
1
D2
0 POR and/or external reset recovery
1 Reserved
0 P31 transition
1 P32 transition
0 P33 transition
1 P27 transition
0 Logical NOR of P20 through P23
1 Logical NOR of P20 through P27
OSC
Figure 40. SCLK Circuit
16
2
Description of Action
SMR, D0
SCLK
TCLK
P R E L I M I N A R Y
Stop-Mode Recovery Delay Select (D5). This bit, if Low,
disables the 5 ms /RESET delay after Stop-Mode Recov-
ery. The default configuration of this bit is one. If the "fast"
wake up is selected, the Stop-Mode Recovery source
needs to be kept active for at least 5TpC.
Stop-Mode Recovery Edge Select (D6). A 1 in this bit po-
sition indicates that a High level on any one of the recovery
sources wakes the Z86L/CX2 from STOP mode. A 0 indi-
cates Low level recovery. The default is 0 on POR (Figure
36).
Cold or Warm Start (D7). This bit is set by the device
upon entering STOP mode. It is a Read Only Flag bit. A 1
in D7 (warm) indicates that the device will awaken from a
SMR source or a WDT while in STOP mode. A 0 in this bit
(cold) indicates that the device will be reset by a POR,
WDT while not in STOP, or the device was awakened by a
low voltage standby mode.
Stop-Mode Recovery Register 2 (SMR). This register
determines the mode of the Stop Mode Recovery for
SMR2.
If SMR2 is used in conjunction with SMR, either of the
specified events will cause a Stop-Mode Recovery.
Note: Port pins configured as outputs are ignored as a
SMR or SMR2 recovery source. For example, if the NAND
of P23-20 is selected as the recovery source and P20 is
configured as an output then the remaining SMR pins
(P23-P21) form the NAND equation.
Z86C72/C92/L72/L92
IR Microcontroller
6-55
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