Apb Peripherals; Table 17: Data Width Of Peripherals - Siemens ERTEC 200P-2 Manual

2.3.10 APB Peripherals

The function blocks connected to the APB have interfaces of differing widths. The table
below shows the access mechanisms supported and the data widths of these blocks.
Bit 31:24 Bit 23:16
8-bit
16-bit
8-bit
16-bit
Access modes that are not permitted (e.g. writing byte by byte / halfword by halfword to
the timer) are not prevented by the hardware, nor are they indicated at the AHB in the
form of an error response or QVZ interrupt.
Access to memory ranges that are not decoded (marked as "not used" in memory map-
ping) triggers IRQ52 (see 2.3.2.14) and ends with a ready signal generated by the APB
address decoder. Write access does not have any effect on the system. Read access
returns undefined data.
Copyright © Siemens AG 2016. All rights reserved
Technical data subject to change
Access modes
Bit 15:8
8-bit 8-bit
16-bit
32-bit
8-bit 8-bit
16-bit
32-bit
32-bit

Table 17: Data width of peripherals

Wait states at the AHB
Bit 7:0 Read
8-bit
2
8-bit
Ready
2
247
Write Function block
IO filter,
0
Boot_ROM
PER_IF (except
0
PER_IF-GPIO)
GPIO,
PER_IF-GPIO,
timer0-5,
F-counter,
watchdog,
0 SCRB,
SPI1/2,
flash controller,
UART1-4,
2
I C,
Host interface
ERTEC 200P-2 Manual
Version 1.0