Slow AMBA Peripherals
13-65
GMS30C7201 Data Sheet
13.10.2Signal Description
The RTC module is connected to the APB.
Table 13-50: APB signal descriptions
describes the APB signals used and produced.
Table 13-51: Specific block signal
descriptions
shows the non-AMBA signals from the block.
Name
Type
Source/
Destination
Description
nPOR
In
External
Power on reset.
PA[4:2]
In
APB Bridge
This is part of the peripheral address bus, which is used by this
peripheral for decoding its own register accesses.
The addresses become valid before
PSTB
goes HIGH and
remain valid after
PSTB
goes LOW.
PD[31:0]
InOut
APB Peripherals,
BD bus
This is the bidirectional peripheral data bus. The data bus is
driven by this block during read cycles (when
PWRITE
is LOW).
PSTB
In
APB Bridge
This strobe signal is used to time all accesses on the peripheral
bus. The falling edge of
PSTB
is coincident with the falling edge
of
BCLK
(ASB system clock).
PWRITE
In
APB Bridge
When HIGH, this signal indicates a write to a peripheral and
when LOW, a read from a peripheral.
This signal has the same timing as the peripheral address bus. It
becomes valid before
PSTB
goes HIGH and remains valid after
PSTB
goes LOW.
PSEL
In
APB Bridge
When HIGH, this signal indicates the RTC module has been
selected by the APB bridge. This selection is a decode of the
system address bus (ASB). For more details, see
AMBA
Peripheral Bus Controlle
r (ARM DDI 0044).
PCLK
In
APB Clock Gen
The slow APB clock used to re-synchronize data transfers
between the 32768Hz clock and the APB.
Table 13-50: APB signal descriptions
Name
Type
Source/
Destination
Description
CLK32KHZ
In
Clock generator
32768Hz clock input. This is the signal that clocks the
counter during normal operation.
SRTCEV
Out
APB peripheral
(Interrupt Controller)
Interrupt signal to the Interrupt module. When HIGH, this
signal indicates a valid comparison between the counter
value and the match register. It also indicates 1Hz interval
with enable bit in control register.
URTCEV
Out
APB peripheral
When HIGH, this signal indicates a valid comparison
between the counter value and the match register. This
signal is used to wake up the GM30C7201 when it is
asleep.
CLK4K
Out
APB peripheral
This signal is used in the power management block.
Table 13-51: Specific block signal descriptions