![](/images/new-backgrounds/1270278/270278151x1.webp)
n
Addressing the Registers
To read or write to specific registers, you must use the register address. Register addresses for HP 75000 Series C
The A16 space is divided so modules are addressed only at locations beginning with C00016 within A16. Allocated for each module are 64 register addresses (4016). The module base address is related to the logical address set by the module’s logical address switch (LADDR). The module address is:
module address 16 = (logical address 16) * 4016 + C00016
For the Microwave Switch modules, the default logical address is 120 (7816), thus the module address within A16=
7816 * 4016 + C00016 = DE0016
For example, to address the Status/Control Register of a Microwave Switch module in an HP E1300/E1301 Mainframe, the command register address is:
[A16 location]16 + [module address]16 + [register offset]16 = 1f00016 + DE0016 + 0416 = 1FDE0416
Reading the Registers
ID and Device Type Registers
You can read the following Microwave Switch registers:
∙Manufacturer ID Register (base + 0016)
∙Device Type Register (base + 0216)
∙Status/Control Register (base + 0816)
∙Channel Enable Register (base + 0816)
ID Register: Reading the register returns: FFFF16. This shows
Device Type Register: Reading this register returns FF2816 if the device is either the E1368A Microwave Switch module, or the E1369A Microwave Switch Driver module.
76 HP E1368A/69A/70A Registers | Appendix B |