pc87591l National Semiconductor Corporation, pc87591l Datasheet - Page 202

• Manufacturer Part Number: pc87591l
• Description: Lpc Mobile Embedded Controllers
• Manufacturer: National Semiconductor Corporation

www.national.com
Embedded Controller Modules
4.13.7 ACB Clock Frequency Configuration
The ACB module enables the user to set the ACCESS.bus clock frequency. The SCLn clock period is set by SCLFRQ in
ACBnCTL2 and ACBnCTL3 registers. This clock low period may be extended by stall periods initiated by the ACB module
or by another ACCESS.bus device. In case of a conflict with another bus master, a shorter clock high period may be forced
by the other bus master until the conflict is resolved.
4.13.8 ACB Registers
For a summary of the abbreviations used for Register Type, see “Register Abbreviations and Access” on page 34.
ACB Register Map
ACB Serial Data Register (ACBnSDA)
The ACBnSDA register is a shift register used to transmit and receive data. The most significant bit is transmitted (received)
first and the least significant bit is transmitted (received) last. Reading or writing to the ACBnSDA register is allowed only
when SDAST in ACBnST register is set or for repeated starts after setting the START bit. An attempt to access the register
in other cases may produce unpredictable results.
Locations: Channel - 1 00 FF60
Type: R/W
Bit
Name
7-0
Bit
Data.
Channel - 2 00 FFE0
7
ACBnSDA
ACBnST
ACBnCST
ACBnCTL1
ACBnADDR
ACBnADDR2
ACBnCTL2
ACBnCTL3
Mnemonic
16
16
6
ACB Serial Data
ACB Status
ACB Control Status
ACB Control 1
ACB Own Address
ACB Own Address 2
ACB Control 2
ACB Control 3
(Continued)
5
Register Name
Description
202
4
Data
3
Varies per bit
Varies per bit
2
Type
R/W
R/W
R/W
R/W
R/W
R/W
1
Revision 1.07
0